What does it mean when a man semen comes out when trying to get a girl pregnant?

Are you serious. It comes out to get a girl pregnant, it must be inside the female at time of ejection. Get a book and a clue. If you are referring to semen coming out of the penis, it is called ejaculation. If you are referring to a portion of the semen coming out of the vagina, it is perfectly normal and does not greatly reduce the probablility of pregnancy.