A comedienne is a woman whose job is to make people laugh — a female comedian. The word was borrowed from French, where the ending marks a woman, the way some older English words did. You still meet it on old posters, in reviews, and in the talk of people who like the French flavour. Though actually, many women who do this work, and many younger speakers, just say comedian for everyone. They feel comedienne puts a woman in a special box she did not ask for. Neither word is rude; the difference is fashion and feeling. If a student only learns comedian, they will still be understood everywhere. Comedienne is the older, marked word you may read more than you hear.