One who begets, gives birth to, or nurtures and raises a child; a father or mother. An ancestor; a progenitor. An organism that produces or generates offspring. A guardian; a protector. A parent company. A source or cause; an origin: Despair is the parent of rebellion. To act as a parent to; raise and nurture: "A genitor who does not parent the child is not its parent\u201d ( Ashley Montagu). To cause to come into existence; originate. To act as a parent.