Alexander Payne has a habit with this. Notably Sideways doesn't have a lot to do with being sideways, The Descendants isn't really overly concerned with the the fact that the leads are descended from King Kamehameha.
The film version of Watchmen does include a superhero team called "The Watchmen" (unlike the graphic novel) but they aren't the protagonists of the film—they were a proposed team that was never actually formed. All of the main characters are independent vigilantes with no allegiance to any team, and (apart from Rorschach and Nite Owl) none of them ever fought crime together.
In Batman Returns there's no indication whatsoever that Batman has been absent from Gotham for an extended period of time nor does he at any point in the film make a grand return of any sort. The title is apparently a reference to the fact that Batman has "returned" to star in another movie.
Batman Forever has the Nygma Tech Box. It looks like a blender with fins, and it's not boxlike at all.
In Iron Man, Stark's first seemed to be mostly scrap iron, but his final is more advanced. He lampshades the trope when he first sees the media nickname:
Tony Stark: Iron Man? That's kinda catchy. Not technically accurate, since it's a gold-titanium alloy, but...
The weapon in Krull is identified as "The Glaive". It isn't a curved-blade polearm, but rather a starfish-shaped throwing weapon. Even if you take the older meaning of "glaive" as "sword" it doesn't fit. Due to the film's popularity, a number of other works have named similar weapons "glaives," such as Warcraft and Blade The Series.
In Dr. Dolittle, Rodney the guinea pig ponders how he came to that name, since he's not a pig, not from Africa, and not an Italian "guinea".
Troll 2 is about goblins, not trolls, and is not a sequel to Troll. Furthermore, there are two different films that go by the title Troll 3; neither of them are about trolls and neither of them are sequels to either Troll or Troll 2.
The word "Gojira" is a portmanteau of "kujira" (whale) and gorilla. Early on in the production, they hadn't decided what Godzlla was going to look like, and the pretty cool name for one scrapped design was eventually combined with a different, really cool design...of a lizard.
Toho's Latitude Zero features a monster named Black Moth. Take a wild guess what the monster is. Go on... Give up? It's a flying lion/eagle hybrid.
The Nine Pieces of Eight from "At World's End" are not coins, but random pieces of junk. This is lampshaded and justified in-universe: they used random piece of junk because the founding pirates were flat broke, and called them "Pieces of Eight" because they thought it sounded more pirate-y than "Pieces of Whatever We Happened to Have in our Pockets At The Time."
The Flying Dutchman, which, unlike in the original legend, does not move through the air, and is not Dutch. Its captain is a Welshman with a Scots accent. Flying in those days, meant fast as often as it meant moving through the air (and very occasionally still does, in phrases such as "flying start"). The equivalent today would be "Racing Dutchman."
Then there's also The Spleen, who named himself after a body part that has nothing to do with his superpower. It may be a play on the saying "Vent your spleen", where you generally let loose with a rather noxious rant. And The Spleen does vent something quite noxious when he uses his power.
The Battle of Endor took place on the forest moon of Endor (which is a gas giant). The Battle of Yavin is slightly better, but not much—it takes place near Yavin IV, which is actually only a moon of the gas giant Yavin.
Many weapons use terminology that is not specifically correct. For example, lightsabers aren't shaped like sabers. There are also blaster rifles, which don't have any rifling. Turbolasers do not fire true lasers. Ignoring the inherent pseudoscience of the futuristic weaponry, new weapons often sport names that are based on older technology, such as "howitzer" being based after the Czech word for sling.
Star Destroyers can neither destroy stars nor qualify as equivalents of naval destroyers, given their sheer size and firepower compared to Rebel ships. They're more akin to battleships or aircraft carriers. Super Star Destroyers are much larger, but still can't destroy stars. Then again, in modern times, Destroyers are typically the most powerful surface combat ships in any navy.
Jedi Knights are really more like warrior monks than they are knights. Unlike traditional knights in the real world, their status is not bestowed by a king or ruler; Jedi are an insular society unto themselves. Nor do they employ titles such as "sir". They also don't own much in the way of personal possessions or property, both of which lords may reward knights for loyalty. Also, knights were very much part of a royal's court, unlike Jedi who were not supposed to be involved in politics. Real knights served the wishes of their lord, lady, or monarch. Jedi do exist to serve, but they serve of their own accord and in whatever way they see fit. They are not really at anyone's beck and call and all VI Ps of the Old Republic know that.
In the movie Revolver, none of the guns are revolvers, and nothing rotates. It's, like, a deep metaphor, ya know?
Zombi 2 (known in America as Zombie, known in some other places as Zombie Flesh Eaters) is not the second "Zombi" film, it's the first in its series. Romero's Dawn of the Dead was released in Europe under the title Zombi, and Italian director Lucio Fulci decided to capitalize on its success by claiming that his film was actually a sequel or prequel. Which it wasn't.
Zombie Holocaust was released in some places under the title Zombi3, trying to do to Fulci what Fulci did to Romero. In other places, including America, it was released under the title Dr. Butcher M.D., Medical Deviate. There isn't a character named Dr. Butcher in the film, and the evil Doctor character only shows up in the finale of the film. Even the titles Zombi 3 D and Zombie Holocaust are rather inaccurate- the film is predominantly about LIVING cannibals, while zombies only show up for small portions of the tale.
Werewolf in a Girls' Dormitory. The werewolf never actually gets into the dormitory. He mostly just wanders around the grounds.
Krakatoa, East of Java. Krakatoa is, in fact, West of Java, but they wanted a more exotic-sounding title.
There are three unrelated films called Madhouse, only one of which is actually set in a mental institution. The 1990 John Larroquette and Kirstie Alley film is about a house being overrun by uninvited guests that could figuratively be called a "madhouse". In the 1974 Vincent Price film, it's a plot point that Price's character was once in a mental institution, but no scenes actually take place there. The Vincent Price one was originally going to be called The Revenge Of Dr. Death or The Return of Dr. Death, both of which would have been more descriptive of the plot, but the producers thought it would be mistaken for a sequel; It didn't help that there had been a recent film called Dr. Death, Seeker of Souls either.
National Treasure: Book of Secrets actually centers on finding a lost city of gold. The Book of Secrets is only a single road sign on the way to it. To put things in perspective, this is like giving the first movie the subtitle of "Ben Franklin's Letters".
Bobby Fischer never appears in Searching for Bobby Fischer. In fact, nobody really searches for him in the film. Searching for the Next Bobby Fischer would have been a more accurate title.
Haunted Honeymoon: The characters are not on their honeymoon. They are not even married yet.
The Dead Are Alive does not feature any undead, despite all the film's advertising trying to convince viewers otherwise. The film actually is a proto-Giallo with characters being offed by a very human killer. In fact, the main character specifically dismisses the possibility of the dead being alive within the first 15 minutes of the movie.
Frankenstein's Bloody Terror is about...werewolves. Fighting vampires. This is actually Handwaved in the prologue, which explains that the family of werewolves that in the film is actually descended from the Frankenstein family. The reasons behind the title change are more interesting than the actual film. The US distributor promised theaters a Frankenstein picture, but ran out of money midway through production. In desperation, they acquired the rights to an unrelated Spanish picture called Mark of the Wolfman, added the aforementioned prologue, and released it hoping that no one would notice.
The Evil of Frankenstein is actually the Hammer Frankenstein film that depicts Baron Frankenstien (as usual played by Peter Cushing) as somewhat sympathetic. He's more of a Well-Intentioned Extremist in an unsupportive world that just thinks that all Science is the work of the Devil. The truly evil character is Zoltan, the hypnotist who tries to use the monster for his own murderous purposes.
Guess what doesn't happen in Toga Party.
Meatcleaver Massacre has nary a meat cleaver in sight.
At no point during Help Me, I'm Possessed is anyone possessed.
In both House of the Dead movies, the first one has a house that's actually a small shack, while the second has an entire college campus.
Clash of the Titans does not in fact involve any Titans, clashing or otherwise. Their existence is acknowledged in the backstory, but by the time the plot starts they've all been defeated. Though it incorrectly refers to a Gorgon's head being used to fight a sea monster as "a titan against another titan."
In How to Train Your Dragon, the dragon Toothless has teeth. Being retractable, they're mostly hidden, and show up when he eats or attacks. Hiccup's father Stoick is not The Stoic. And Hiccup never gets hiccups (though in the series it's explained that runts are named Hiccup.)
The Pink Panther movies are not about a feline. The "Pink Panther" is a diamond that plays a major role in some, but not all, of the films. The cartoon panther that originally appeared in the first film's credits, also called The Pink Panther, took on a life of its own as a film and TV cartoon character and advertising mascot.
At no point in the Alone in the Dark (2005), are any of the characters ever alone in the dark. They are either with someone else at the time, or they are not in the dark. The film was based on a video game in which the player character is alone in a haunted house.
The Swedish movie November 30 actually takes place around June 6 the National Day of Sweden. The title comes from the fact that it's theme is Neo-nazism and November 30 is a date when Swedish neo-Nazis often march to commemorate the death of king Charles XII.
Witchfinder General was also released as The Conqueror Worm despite having little to do with the Edgar Allan Poe poem, although a portion of it is recited toward the movie's end. Vincent Price was in it, so presumably it was titled that way to attract fans of all the Roger Corman-directed Poe adaptations he'd starred in.
Mr. Green in Clue. All of the other guests have Meaningful Names that reflect their appearance or attire, but Mr. Green does not wear green or have green eyes or hair. In some versions of the film, he's under an assumed identity, and therefore a "plant."
The sequel to The Blair Witch Project was called "Book of Shadows", even though there was no such mention of any Book of Shadows in the film.
Musa, called The Warrior in English, is not about one specific warrior. It has an ensemble cast, with three characters that more or less share the main spotlight.
The Terry Gilliam movie Brazil does not have a single scene set in Brazil, nor is the country relevant to the plot in any way or even mentioned once. Its only significance is that an old song titled "Brazil" is played throughout, perhaps because its romantic imagery provides a thematic counterpoint to the bureaucratic police state in which the story takes place.
In Airheads, Chazz's rock band has three members and is called The Lone Rangers. Ian the DJ points out that they would more accurately be called The Three Rangers.
The Room is not about a room. It does have a great many scenes taking place in Johnny's apartment, but it is not the focus of the film at all. If you take director/writer/star Tommy Wiseau's word for it, it's about Johnny's Happy Place, but even that doesn't make a whole lot of sense.
Rain Man is not about a man who is associated in any way with rain. "Rain Man" was what Charlie called Raymond when he was a little kid when he misremembered Raymond as an Imaginary friend named Rain Man
The Hong Kong film Hak se wui yi wo wai kwai is known as Election 2 in English. It isn't a sequel to the American film Election or any other film. The American release fixed this by naming the film Triad Election.
A Justified Trope in Godzilla (2014). M.U.T.O. stands for "Massive Unidentified Terrestrial Organism," and it originally described the so-labeled beast pretty well. However, the label became obsolete with a recent development, in which Stenz describes the creature as "no longer terrestrial" in movement. It still applies to the female one, however.
Sorcerer isn't about a sorcerer. It's about truck drivers transporting nitroglycerin in a truck named Sorcerer.
Snatch: The man known as Boris the Blade, Boris the Bullet-dodger and Boris the Sneaky Fucking Russian is an Uzbekistanian who prefers to fight with guns and doesn't so much dodge bullets as absorb them.