noun.
Unselfish concern for the welfare of others; selflessness.
noun.
Instinctive behavior that is detrimental to the individual but favors the survival or spread of that individual's genes, as by benefiting its relatives.
The Century Dictionary and Cyclopedia
noun.
A term first employed by the French philosopher Comte to denote the benevolent instincts and emotions in general, or action prompted by them: the opposite of egoism.
the GNU version of the Collaborative International Dictionary of English
noun.
Regard for others, both natural and moral; devotion to the interests of others; brotherly kindness; -- opposed to egoism or selfishness.