Here's something interesting in the Vocabularia da lingoa de Iapam:

Ienxǔ. Os da ſeita dos Ienxùs.

Zenshū. Those of the sect of the Jenxùs.

The initial <I> is "consonante", equivalent is the sound that in Hepburn romanization is written <j> in contemporary Japanese. I mentioned last time that the stage of the language described by this dictionary palatalized the /se/ mora, so you get shamishen instead of shamisen. The same went for the voiced version of that mora, giving jen instead of zen.

But the most interesting thing is that they define Zenshū 禅宗 "Zen sect" not by describing it but by referring to a loanword they already had: Jenxù, plural Jenxùs — and that loanword itself was probably from Zenshū!

Somewhat similarly, the dictionary uses the word fotoque (hotoke 仏, "buddha") in many definitions, such as nenbut (nenbutsu 念仏), defined as "Chamar, ou inuocar o Fotoque" ("call or invoke the Buddha"). But it does not have a definition for fotoque itself. I guess these were the sort of words that you were supposed to know by the time you arrived at your posting.