To dissuade someone is to talk them out of a plan — to push them, with words, not to do it. It is the opposite move from persuade: persuade tries to get a yes; dissuade tries to get a no, or a stop. It is a little formal. In everyday talk, people say talk out of. You dissuade a friend from driving after drinking; a parent might try to dissuade a child from dropping a class. The pattern is dissuade someone from doing something, not dissuade someone to do something. Success is not promised: you can try to dissuade a person and still fail. The word is about the attempt to turn them away, not about forcing them.