Since you mentioned Cain...Jean CA(u)IN of Noyons who formulated Calvanism changed his name from Cohen > Cauin > Calvin.

Another bit about Cain/coin/koin... https://en.wikipedia.org/wiki/Koin%C3%A9_language from koinos (common, public, shared, general, ordinary) which also implies a private language.

Edit: almost forgot...Cain from Hebrew Qayin - "created one" aka based on creatio ex nihilo (creation out of nothing).

Since you mentioned Cain...Jean CA(u)IN of Noyons who formulated Calvanism changed his name from Cohen > Cauin > Calvin.

Another bit about Cain/coin/koin... https://en.wikipedia.org/wiki/Koin%C3%A9_language from koinos (common, public, shared, general, ordinary) which also implies a private language.

Edit: almost forgot...Cain from Hebrew Qayin - "created one" aka based on creatio ex nihlo (creation out of nothing).

Since you mentioned Cain...Jean CA(u)IN of Noyons who formulated Calvanism changed his name from Cohen > Cauin > Calvin.

Another bit about Cain/coin/koin... https://en.wikipedia.org/wiki/Koin%C3%A9_language from koinos (common, public, shared, general, ordinary) which also implies a private language.