This trailer for Gentleman Jim, a 1942 film about the boxer James J. Corbett raves that the title character "made old San Francisco gayer" and "always did his best work in the clinches". After all, he was "the most fabulous figure of old San Francisco" and this is the "gayest picture" of the decade. He's also got "blarney on his lips" and "can lick any man in the world", apparently.
The trailer of The Great Race calls the film the gayest comedy in the world.
Well, there is Prince Hapnick (one of the two characters played by Jack Lemmon) ... "Goodbye, you Great Leslie, you!"
"Weird" has changed its meaning a bit through overuse of the word in advertising media. Originally, it meant something more along the lines of "scary" and "supernatural", and has since been watered down to "sort of generically eccentric". That's why you occasionally see old comics and pulps with names like Weird Tales or Weird Mystery. As in "the weird and haunted shores of World's End" (Pirates of the Caribbean).
Ironically, it's now taken the spot in the language originally occupied by 'queer'.
Some examples never bother to change with the times. The Golden Gaytime is an ice cream bar that's still proudly displayed in Australia. Much beloved of backpacking Brits with Facebook accounts. The jingle, which is still played in ads, in Australia, today, states "It's so hard to have a Gaytime on your own!" The front of the box feature the words "4 chances to have a gay time!"
The 1941 musical comedy film All-American Co-Ed was billed as "the season's gayest musical". It probably doesn't help matters that the movie's plot centers around a young man who infiltrates an all-girls school Disguised in Drag.
AYDS. "Why take a diet pill, when you can enjoy AYDS."
This commercial exemplifies how people used to refer to being "retarded" in the clinical sense before the word became a common insult.
Cockburns is not pronounced the modern way, and is not the kind of product one might think it to be if it were pronounced that way. (What that kind of product might be shall now be left to your imagination, where it may be infinitely worse.)
Here's a 1970s spot for a Mego board game called Ball Buster, in which you "try and bust your opponent's balls." Doubles as Getting Crap Past the Radar when you consider that the meanings were exactly the same back then.
A 1908 soap ad asked "Have you a little fairy in your home?"
Fairy Soap is still around. One of Proctor & Gamble's most popular international brands. The Little Fairy ad could still be seen in the 1970s.
A Kool-Aid commercial from the 1950s has a mother saying, "You can give your youngsters a lot of pleasure with Kool-Aid." Needless to say, "giving someone pleasure" has a very different meaning nowadays...
This commercial for a boat brand called Johnson tries to make it sound like the boat is part of the family. That still gets across, but it occurs to one that "Johnson" may have just been a name at the time...
One designer posting at Clients From Hell had to deal with a client who wanted a new sign for the restaurant owned by his family. It would proudly bear the slogan his grandfather created back in the day: 'You'll love the taste of our wieners.'
This film from Nestle's anthology promoting wellness features a Filipino student participating in a declamation contest using "The Owl and the Pussycat" by Edward Lear. Wait until around 5:50, where the adults are coaching him over and over again on the proper way to say "Pussy", or rather, "What a beautiful Pussy you are!".
"Nothing sucks like an Electrolux"-brand vacuum cleaner. Apparently the innuendo was intentional but it was nice having this trope to hide behind.
The Golden Gaytime is an ice cream bar that's still proudly displayed in Australia. Parodied in Pulp Sport, where occasionally, the (male) loser to the coin toss had to dress as a promotion girl and walk around offering people the ice cream. "Would you like a Gaytime?"