hydrogen
The element hydrogen was named in Greek in 1783 for one of its only known properties when it was discovered: if you burn hydrogen gas, it produces water. I’d never thought to analyze its parts before I learned this: hydro- + -gen, of course!
In particular, I love the German word for it, a calque: Wasserstoff. Imagine if things had gone very slightly differently, English had also taken this approach, and we said “waterstuff” instead every time we now say “hydrogen”. Or “smotherstuff” instead of “nitrogen”, and so on…
blurb
The term blurb was invented by comedic writer Gelett Burgess in 1907 as the name of a fictional young woman blatantly promoting his book. This act of blatant self-promotion on the back flap of a book cover eventually generalized to “short promotional quote” in part due to its ridiculous name.
ixnay
Despite its ultimate origin as the Pig Latin translation of “nix”, “ixnay” feels like a distinct word to me. I could see using it in conversation, while “nix” feels like it went out of style a hundred years ago. Today I learned that its enduring use may be due to its frequent use in Three Stooges films, along with “amscray”.
Growing up in the 90s, “oopid-stay” also feels like it’s in the language to me, though I don’t think I’ve ever used it in conversation.