it stems from the same latin routes as things like “Parlez vous Francais?”.

parlez, the french route of a verb,meaning “to speak”.

cant remember the latin word right now though, lol. just the french one.

(patois usually means something to do with regional dialect, such as words that arent words from a literary standpoint, but are used in specific regions of a country, not usually a group of specialized people, such as lawyers or doctors).

Although when I looked up parlance, it stated that it means speech.

Patois : the characteristic special language of an occupational or social group