Also, “C-Note”, I realized after I read you post that this is probably not current usage, the younger people call them “Benjamins”. It originated sometime after World War One as slang, based either on C as short for ‘Century’ or as short for Latin for a hundred, ‘centum’. I suspect given the educational level of most yeggs, thugs, hoodlums and goons of the twenties it was the former rather than the latter.
I recall reading years ago about Sinatra, telling one of his entourage to “Duke him a C note” or “Duke him a hundred” when he wanted someone tipped.
Finally, as long as we're talking about C-notes, remember the “Kansas City Bankroll” or “KC Roll” - a wad of singles with one or two C-notes on the outside, rubber banded and flashed to make people think you had a lot more money than you did.
...Latin for a hundred, ‘centum’...
I imagine relatedly, C is the Roman numeral for 100