A confidant is someone you tell your secrets to, or talk to about private, personal things, because you trust they will not pass the story on. It can be a friend, a brother, a teacher; the point is trust, not a job title. The word is a little formal and bookish — in speech people often just say a close friend, or someone I can talk to. English borrowed it from French. It can be a man or, in modern use, anyone. Though actually, it is one letter away from confident, which means sure of yourself. They share an old Latin root about trust, but today they do different work: one is a person, one is a feeling.