1853, "unselfishness, opposite of egoism," from Fr. altruisme, coined or popularized 1830 by Fr. philosopher Auguste Comte (1798-1857), from autrui, from O.Fr. altrui "of or to others," from L. alteri, dat. of alter "other" (see alter). Apparently suggested to Comte by Fr. legal phrase l'autrui, or in full, le bien, le droit d'autrui. The -l- is perhaps from the L. word.