The Collaborative International Dictionary of English v.0.48:

Unselfish \Unselfish\
   See selfish.

WordNet (r) 3.0 (2006):

unselfish
    adj 1: disregarding your own advantages and welfare over those
           of others [ant: selfish]
    2: not greedy

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "unselfish":
   Olympian, altruistic, bighearted, bounteous, bountiful, candid,
   charitable, committed, consecrated, dedicated, detached, devoted,
   disinterested, dispassionate, free, freehanded, freehearted,
   generous, giving, gracious, greathearted, handsome, hospitable,
   humanitarian, humble, impartial, impersonal, large, largehearted,
   lavish, liberal, lofty, magnanimous, modest, munificent, neutral,
   open, open-handed, openhanded, openhearted, philanthropic,
   princely, profuse, sacrificing, self-abasing, self-abnegating,
   self-abnegatory, self-denying, self-devoted, self-effacing,
   self-forgetful, self-immolating, self-neglectful, self-neglecting,
   self-renouncing, self-sacrificing, self-unconscious, selfless,
   stintless, unacquisitive, unbiased, ungrudging, uninfluenced,
   unpossessive, unpretentious, unsparing, unsparing of self,
   unstinted, unstinting, unswayed