Whilst doppelganger these days can just mean someone that looks like you that's a case of the original definition becoming more generalised over time. The word is derived from stories of ghosts called doppelgangers that looked like someone you know.
After "Yuppie" for the next one (60s counter culture) I typed "Yippie" about ten times (sometimes making it "Yippee") before remembering the actual answer that word was derived from.
I liked how some rhyming answers were next to each other: Kipper and Skipper. Sapper and Grappa. Also, I was going to be one answer short, until I filled in the very last answer (clothing) which reminded me what the ghost one was.
It's still used in the British Army. The lowest rank in the Royal Engineers (equivalent to Private) is Sapper. The corps as a whole are colloquially known as the Sappers.
Only reason I got it is because of recently watching the British series "Danger: UXB" about WWII soldiers in London who went around defusing UneXplodded Bombs that the Germans had dropped on the city. Quite good.
No one else ever play the board game Stratego? Used to have it as a kid. Sappers were weak but the only pieces that would defuse enemy bomb pieces instead of dying to them. Was so satisfying if you managed to sneak a sapper to an enemy bomb without dying on the way. Happy days... :)
(I am not suggesting this should be accepted)