A character may have no apparent interest in the opposite sex. They may live in a single-bedroom apartment with one of their "roommates". If the character is male, he may lisp more than someone missing two front teeth, have a limp wrist and an interest in fashion and musicals. He may be unusually fastidious in dress and grooming. He may even profess a great knowledge of modern dance. Conversely, a female character may have a deep voice and an aggressive manner, dress in "unfeminine" clothes and play rough sports. But nobody will ever come out and discuss the character's sexuality.
Yes, the character is Ambiguously Gay—they display many stereotypes associated with gay and lesbian people, but the "g" and "l" words are avoided entirely. Characters such as this are usually played entirely for laughs, with "hints" regarding their sexuality being portrayed as jokes in and of themselves. Often the victim of numerous instances of The Un-Reveal. These characters are often played for laughs, usually only for a single episode as a Running Gag, but they can also be full-fledged recurring cast members as well. Lately, it has become somewhat popular to make the Ambiguous Gay a child or teenager, waving away the character's questionable sexuality as them still trying to figure it out - yet still playing their mannerisms for laughs.
Because of less restrictive rules of media and acceptance of homosexuality becoming more common, modern media (unless it's aimed at children) will be more likely to open the sexuality of their characters, making it a Broken Trope. Don't expect this type of character to ever be the hero of a children's production, though you'll notice plenty of villains—and sometimes sidekicks—who wear their ambiguous sexuality on their sleeves.
Compare Hide Your Lesbians, where the characters may not act in a stereotypical manner, but their relationships are never outright stated or displayed (except maybe by Word of Gay). The writers in charge of works focused on Heterosexual Life-Partners may play around with this. Ambiguously Bi is related, but occurs when a character displays interest in more than one gender.
Also compare/contrast with Mistaken for Gay, Transparent Closet, and some types of Have I Mentioned I Am Heterosexual Today?, in which the character's dubious sexuality is much more openly questioned. Also compare Real Men Wear Pink, where a character is very manly but has one or two girly interests. Compare Have You Tried Not Being a Monster? for when gay innuendo is used to define something supernatural, such as vampires or mutants. Contrast with Flying Under the Gaydar and Straight Gay. If the character is revealed to be one hundred percent straight, then they're Camp Straight. Asexuals of all romantic orientations, with their general lack of interest, often fall victim to it (and all its contingent repercussions). This trope is not synonymous with Ho Yay; nor does the character ever need to be declared gay by the work's creator or creators to fit the definition.
Budweiser ran one of their happy, feel-good ads where the first person that a male soldier calls to tell he's coming home is another guy who he also embraces first at his coming home party, even before his own parents.
Cacofonix from Astérix. He is the only male villager to have neither a wife nor occasional love interests (other than Getafix, as druids don't marry), he plays up to stereotypes of camp, self-declared artists, and in Asterix and the Secret Weapon, while living in the forest with the rest of the village men in an all-male society, there are love letters pinned to his tree.
The Joker of Batman fame. Since Harley's transition from the DCAU into canon comics, the writers have been seemingly trying to tear them apart and made it into a one-sided relationship on her part. Harley & Ivy both think that The Joker only has eyes for Batman. Joker has often professed affection towards Batman (complete with moments of desperate attention-needing) and has made some awkward comments about Robin's shorts and shaving habits. He seems to have quite a flirtatious love/hate thing for Lex Luthor as well. The Joker is also very keen on his appearance and once said he didn't want to see Batman until his nails were finished drying, and in another instant took off his pants in front of Onomatopoeia and told him that he "bottoms from the top". As counter-evidence, The Killing Joke showed the not-yet Joker's pregnant wife saying that he was "good in bed", but the entire segment falls into his Multiple Choice Past. In Arkham Asylum: A Serious House on Serious Earth Joker slaps Batman on the butt and continually hits on him throughout the comic. The pages are lined with homoerotic content and an unnatural level of sexual tension. (Arkham is non-canon, though its status as one of the iconic Joker portrayals means it can't be discounted because of that.)
Various Batman media have run with this. Batman (1989) shows that Jack Napier, the man who became the Joker, had more than a casual interest in art and was very keen on his appearance. In The Dark Knight, the Joker disguises himself as a white-skirted nurse to blow up a hospital and, in his last meeting with Batman, looks forward to many future encounters with him and tells him: "You complete me." Batman: Mask of the Phantasm has him bat his eyelashes when he sees his old mob boss for the first time in years.
Batman himself borders on this or Ambiguously Bi at times. Some writers make the Batman/Joker Foe Yay go both ways (as if it wasn't disturbing enough) and portray Batman as having some bizarre obsession with the Joker. Frank Miller writes Batman as being gay but simply sublimating his sexual urges into crime fighting, which caused Miller to joke "He'd be a lot healthier if he was gay".
In an issue of The Flash, the Pied Piper (who is an openly gay villain) is shown to be offended by the insinuation that Joker might be gay, and postulates that such a sick, depraved man is likely incapable of feeling love of any kind.
The Creeper. With DC Comics' original run, this was probably unintentional, but it's difficult to believe that it was. The title character appears to be wearing nothing but boots, gloves, briefs, and a feather boa, reveals himself (briefly) to be a masochist, and likes to shock his enemies with his flamboyant mannerisms. Somewhat less stereotypically, The Creeper's civilian persona, Jack Ryder, has a dislike bordering on hatred of female affection and immediately takes his male coworker up on his offer to buy an apartment together. His origin story explains his costume as being what he could drum up on short notice at a costume shop (all the good costumes were already rented, and what he got was a box of odds and ends) and his mannerisms as him realizing that the bad guys were freaked out by his appearance and deciding to just run with that. None of this is proof that Jack isn't gay, of course.
Gil Thorp: Lini Verde, a flashy-dressing Glee fan who's also a clinch player for the basketball team. His sexual orientation hasn't been stated. The storyline involves a website that calls him unpleasant names, but the exact nature of those names is unrevealed (probably a good idea for all sorts of reasons). When one character suggests wearing pink to support him, she gets the response "This is about bullying, not ... pinkness!"
It's Grim Up North London: Jez and Quin in the Private Eye comic strip. Maybe they're a stereotyped gay couple; maybe they're an equally stereotyped pair of upper-middle-class artistic types, who happen to share a flat.
In Secret Six, Catman and Deadshot are initially BFFs who other characters jokingly say are in love, but the final issue implies that they may legitimately be in love with one another. Word of God confirmed that Catman at least is bisexual, while Deadshot's not so certain.
The Marvel Comics supervillain Man-Killer from Thunderbolts was... actually not that ambiguous, but the comics spent years not stating it directly. Aside from her name, her stereotypically butch appearance, and her firm rejection of any men who showed any interest in her, there's this little exchange from when she decided to try being a good guy.
Cyclone: One more goes to the other side... Man-Killer: I was born on that side, Frenchie. Cyclone: I meant — oh, never mind.
Adrian Veidt, of course. The movie version fits the trope fairly well, the book a bit less so.
Rorschach: He is pampered and decadent, betraying even his own shallow, liberal affectations. Possibly homosexual? Must remember to investigate further.
Rorschach: The "holding a handshake too long" scene that demonstrates Nite Owl II's sexual tension for Silk Spectre II is mirrored later with confirmed bachelor Rorschach doing the exact same thing to Nite Owl II. Plus he has mommy-issues and possibly idolizes his dad.
Wonder Woman: Some of the Amazons are Ambiguously Bi, the rest are Ambiguously Gay. Post-crisis, it is revealed that most residents of Themyscira are the immortal reincarnations of women who were wronged or abused by men and are all (mostly) misandric as a result, giving them a Freudian Excuse for avoiding men.
The title character of Yoko Tsuno never appears to have a boyfriend, but she eagerly bonds with cute young women throughout the series, which makes quite a few fans wonder about her sexual orientation. In later albums the author tries to couple her with her best friend Vic, even though they don't even have a fraction of the chemistry Yoko has with some of the other girls — especially Ingrid.
Spider-Man villain Mysterio is sort of this. In the mainstream comics he's rarely, if ever, shown any interest in women and has had a few hints over the years (plus the Spidey standard of occasional Foe Yay). Some novels dropped the ambiguously part and made him explicitly gay; said novels are dubiously canon at best but pretty much everyone out-of-universe assumes he's gay at this point, even if the comics have yet to actually say it.
Early in With This Ring, whether or not the SI was attracted to Superboy, or just over-protective, was a point of debate.
The WWE tag team Billy & Chuck were ambiguously Manly Gay, from being spotted backstage oiling each other up and doing bizarre stretches, to their shiny red trunks and matching personalized headbands, to their boy-band entrance theme. This became less ambiguous when they planned a gay wedding, on television — and then became outright subverted when they stopped said gay wedding to declare that the whole thing was a publicity stunt, and they weren't really gay, just Heterosexual Life-Partners.
Their manager Rico, who took their gimmick AND their theme song to whole new levels. The You Look So Good To Me theme has been used time and again in the WWE to mark a character as non-heteronormative. See Marella, Santino.
Long before Billy & Chuck, WCW had Lenny and Lodi, who were very ambiguous about their "very close relationship" - until Executive Meddling from AOL T Ime Warner killed the angle, ending it with the revelation that they were brothers.
While The Brooklyn Brawler's onscreen persona has always been a tough guy, an Urban Legend amongst longtime wrestling fans is that Steve Lombardi is gay, rumored to be in a relationship with Pat Patterson.
During a D-Generation X run, Triple H and Shawn Michaels seemed to pass off as convincing Heterosexual Life-Partners at the very least. They only even somewhat pass because most viewers don't remember the original DX, where there was very little heterosexuality to be had, between Shawn kissing Hunter on national television numerous times and Hunter's infamous "bi" quote:
Goldust from the WWE, even though his homosexual overtones are primarily mind games he plays with his opponents. One notable example is his feud with Razor Ramon, where in one match he rubbed Ramon's chest and freaked him out.
Too Much had "Too Sexy" Brian Christopher and Scott "Too Hot" Taylor as tag team partners who were very concerned about each other's safety. Billy & Chuck's "wedding" angle was originally planned for Too Much, but was vetoed by Jerry Lawler (Brian Christopher's father) who was afraid his son's career would never recover. However, they found more success when the then-WWF repackaged them as the Pretty Fly for a White Guy team Too Cool, Grandmaster Sexay and Scotty 2 Hotty and put them with Rikishi, and it got over much more than Too Much had.
Round the Horne has Julian and Sandy: a couple of out-of-work actors, though they could turn their hand to anything. In one episode they were lawyers, leading to the glorious line "We've got a criminal practice that takes up most of our time." (At the time, homosexuality was still technically illegal in the UK.)
Bittersweet Candy Bowl has David, who adores Abbey according to the chart. And this◊ or this makes it seem that David likes touching Abbey while having fun.
Bob and George takes the perceived Ho Yay between Zero & X in Mega Man X and runs with it. While X and Zero angrily deny this, plenty of humor comes from them being way too affectionate and concerned with each other, and entering into oddly ambiguous banter. Many other characters often debate if they're gay or not the second they leave the room, and Bob at one point actually referred to them, upon their entrance, as "The Ambiguously Gay Duo".
Mikey Hopkins (whom Mike Sopkins of Funny Farm is an Expy of) hits this trope even harder. He's tackled near-daily by what is generally regarded as, at the least, a very foxy lady. And then he complains about being behind on his plans by thirty-seven seconds.He did tell her he was gay in one of the last few storylines, and explains that he became a Schedule Fanatic to prevent himself from having to think about it. "Oh! And you're always pressuring others to work hard too so you'll fit in?" "No, I'm just a perfectionist. This doesn't define ALL my traits, you know."
Tedd, despite looking rather feminine and even recreationally spending some of his time as a woman, is not only totally straight, but mildly homophobic (because everyone thinks he's gay). He's trying to get past the latter, though.
Played for drama with Nanase, despite it seemingly starting out as a joke. She however is the genuine article.
Prince Tramennis of Jetstone, a Bishounen diplomat in a family of chiseled warriors, who comments on his brothers' fashion tastes, annoys his father, and rocks some low-grade Zettai Ryouiki. When he communicates with Charlie, the latter's idea of A Form You Are Comfortable With inevitably involves rainbows. But it's never quite discussed, and it might just be a non-issue for Erfworlders, given how their reproduction works.
Ace Hardware and Cubbins, with such doozies as, "The Magic Kingdom had been Ace Hardware's occasional refuge... He and Cubbins would usually come here and... Oh, man. Cubbines. They were enemies now, right? Aw, no." May be a bit of a subversion since Ace Hardware generally comes off as a tough military sergeant type Gadgeteer Genius. Cubbins has enough stereo typically gay traits, though.
Funny Farm: Mike Sopkins spent a lot of time frolicking gaily through this trope. And, of course, ended up being revealed as utterly straight, if unbelievably innocent about sex in general; in fact, Ridley is afraid to come out to him.
Conrad is all over this one. Violent aversion to women? Check. Tight, fashionable clothing? Check. Apartment in the "artsy" side of town? Check. But nothing's yet been stated straight out.
Doc Worth, with his fabulous (though probably a little grungy) fluffy pink coat. And his ambiguously Slap-Slap-Kissrelationships with both Lamont and Conrad.
Hanna: Yanno, actually Worth is kinda keen on you now. Conrad: WHU-? What.
Mayonaka Densha: Jack is oft none too subtly hinted to be attracted to Tom, is constantly teased about it by Hatsune and is also a raging misogynist. Nothing has been stated outright although it's justified, given the setting.
Noblesse: Frankenstein, M-21, & Tao. Frankenstein revolves around only one man, Raizel, & he spurned the pretty Dr. Aerith. M-21 has a lot of fangirls, but doesn't know they exist, is very emotionally attached to M-24 & only seems to have fun around other men. Tao is an ambiguously bi semicrossdresser who wears a woman's offshoulder sweater, paints his nails, wears eyeshadow, & has a fondness for Ik-Han (boy) & Seira (girl).
Ja Wangnan from Tower of God. He and Viole are not Distracted by the Sexy that is Yeon, but that might be because the first impression she gave him was accompanied with her accidentally burning him and making him drop out of a test. The real reason why people think he might be gay is because he saved Nia's number under "My Beloved Nia ♥".
The Scumthorpe Files: Davina, the snarky alien girl. She's outright stated that she would date Nikki, even referring to her as "strangely pleasing to look at". This would make you think she's a lesbian, but Davina's love of Trolling people sort of leaves it unsure. The fact that damn near everyone thinks Nikki is hot doesn't help.
Don't Fear The Dark has Lieutenant Starkey.
Dragon Ball Z Abridged plays Zarbon's ambiguous sexuality for as many jokes as it can. Soon before his death however it is revealed, to the surprise of everyone, that he is completely straight.
Coach Z of Homestar Runner was shown married to Bubs and has worn a skirt and hair curlers in two different toons. The only reason why he is ambiguous is because his sexuality is never mentioned. He's likely Ambiguously Bi due to his obsessive attraction to Marzipan.
Barry 'The Blender' Henderson and Thomas 'The Tanker' Smythe of I Am Fighter both fit to some extent; Thomas frequently takes it to Squick levels.
Omega Zell from Noob is a reporter for a feminine channel in real life, cares for his avatar's appearance over anything else, is frequently forced into an Involuntary Dance and acts as if he has a crush on the game's (male) top player. His Yaoi Fangirl guildmate speculated he could be gay from day 1, but he has always denied it. Season 4 has him reveal that he's deliberately avoiding relationships with women to be able to focus on his dream of becoming the next top player of the game (that and he sort of hates them). However, neither the series creator nor the fans seem able to stop making jokes about him having a crush on any male character whose actor ends up in close proximity to him on "behind the scenes" photos.
Chapter 21 of Psychronicles. Is it so hard to guess who?
Red vs. Blue has Donut. In Season 1, he had been given pink armor ("It's not pink, it's lightish red!") and was your typical new recruit. In Season 2 (where this trope comes into play) he started using lotions, talking about his feelings, screaming like a woman, analysing dreams, and generally being as effeminate as possible while retaining some air of heterosexuality. The song "Donut: The Musical" from the Season 9 soundtrack is full double-entendres and similar sounding words (that the other Red members keep asking to repeat). In the show itself Donut stopped being ambiguous around Season 3.
Tucker: I don't think Santa's outfit is a biker's costume and a codpiece, Donut. Donut: It was the best Christmas ever!
Jean-Armand (codename: Nephandus) of the Whateley Universe is obsessed with his looks and his hair and his clothes. Chaka refers to his standard outfits as a 'Merchant-Ivory wardrobe'. A mama's boy, although his mother is a notorious European supervillain called the Troll Bride. Carries a walking stick (although it's a weapon too). Even his friends in the Bad Seeds make jokes about his ambiguity.
Pegasus is an even stronger example of this trope than the original. He goes so far as to violently defend this image, as once the side characters find out that Pegasus had a wife, he knocks them unconscious with the words "I can't have people thinking I'm straight".
Bakura, to the point where his own personalities can't agree on the issue.
Bakura: I'm not gay, I'm just British! Yami Bakura: I'm not British, I'm just gay.
Marik is either in a Transparent Closet or out and dating Yami Bakura, although it's less ambiguous and more Marik failing to even realise he's gay.
Marik: Oh, what, just because a guy likes to dress effeminately and hang around with another extremely attractive man and read yaoi and flaunt his gorgeous abs and stroke a phallic symbol suggestively in every other scene, that automatically makes him gay?! Bakura: ...Kinda.
The writer of faith-based LGBT pride blog We are the Rainbow, Bess, has hinted at being a lesbian, but a recent blog post Lampshaded her ambiguous sexuality and choice not to reveal whether or not she is a lesbian.