ETYM French altruisme (a word of Comte's), Italian altrui of or to others, from Latin alter another.
Principle of regard for others; self-sacrifice.
In biology, helping another individual of the same species to reproduce more effectively, as a direct result of which the altruist may leave fewer offspring itself. Female honey bees (workers) behave altruistically by rearing sisters in order to help their mother, the queen bee, reproduce, and forgo any possibility of reproducing themselves.
The quality of unselfish concern for the welfare of others; SYN. selflessness.
Acting with less concern for oneself than for the success of the joint activity; SYN. self-sacrifice.