unselfish/selfless, showing a concern or interest for the well-being of others;
e.g. The community leader is altruistic and works tirelessly for the welfare of his subjects.
(adjective)
relating to a nature of animal behavior that involves the animal acting in ways that may be non-beneficial or even harmful to itself but beneficial to other members of its species;
e.g. The mother bear was altruistic because she gave all of the food to her cubs and put her life in danger to protect them.