The feminine of confidant is confidante, probably due to the French origin of the word (confident, whose feminine is confidente). I wonder which other words of foreign origin commonly used in English have kept their original feminine?
Edit: so there may be entire categories of such words, of course, I should have thought of that. Do people have examples other from languages other than French, Italian and Latin? I was trying to think, for example, of a pair of such words of German origin, but can't find any.