> Is bourses crypto jargon

Much older than that, it's more general finance jargon. The relevant definition[0] is:

"A stock exchange. (figuratively) Any place, real or imagined, where the value of a thing is settled."

[0] https://en.wiktionary.org/wiki/bourse

It's a common term for a stock market in non-English speaking countries.

Bourse in French means a sac/purse, scrotum, a scholarship, a market, and the stock market. Not sure what the origin is but it's not Latin.

Edit: It's from Greek inspired mediaeval Latin bursa meaning leather

It translates to market or marketplace