In the 90s, when everyone started using the word fat/phat, I found out from an article that it's usage that way could be traced back to 1920s jazz musicians. Everything old is new again.
I always thought the word "ginormous" (a portmanteau of gigantic and enormous) was totally modern, but then I read a book published in 1943 by a Battle of Britain Spitfire pilot which had "ginormous" in its glossary section.