The following are some words that were once used all the time a generation or two ago but now sound ridiculous whenever somebody uses them. But guess who's going to START using them? This guy...
bloomers (n): ladies' underwear
bee's knees (adj): neat, cool
dapper (adj): describes a fancy dresser
gentleman caller (n): boyfriend
knickers (n): kids' short pants
settee (n): small sofa
thither (adv): over there
zounds! (int): expression of surprise
I forgot all about "bee's knees." That's fantastic! Are there any more you can think up, especially you older folks out there? Hit up the comments!