The Collaborative International Dictionary of English v.0.48:

Disinterested \Dis*in"ter*est*ed\, a. [Cf. Disinteressed.]
   Not influenced by regard to personal interest or advantage;
   free from selfish motive; having no relation of interest or
   feeling; not biased or prejudiced; as, a disinterested
   decision or judge.
   [1913 Webster]

         The happiness of disinterested sacrifices. --Channing.

   Syn: Unbiased; impartial; uninterested; indifferent.
        [1913 Webster]

WordNet (r) 3.0 (2006):

disinterested
    adj 1: unaffected by self-interest

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "disinterested":
   Laodicean, Olympian, abstract, aloof, altruistic, apathetic,
   ataractic, benumbed, blah, blase, bored, candid, careless, casual,
   colorless, comatose, committed, consecrated, dedicated,
   desensitized, detached, devil-may-care, devoted, dispassionate,
   disregardful, distant, dull, easygoing, equitable, evenhanded,
   fair, heartless, hebetudinous, heedless, hopeless, humble,
   impartial, impassive, impersonal, in a stupor, inattentive,
   incurious, indifferent, inexcitable, insouciant, just,
   lackadaisical, languid, lethargic, listless, lofty, mindless,
   modest, negative, negligent, neutral, nonchalant, numb, numbed,
   objective, open-minded, passive, perfunctory, phlegmatic,
   pluckless, pococurante, poker-faced, reckless, regardless, remote,
   resigned, 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,
   slack, sluggish, soporific, spiritless, spunkless, stoic, stolid,
   stupefied, supine, torpid, turned-off, unacquisitive, unanxious,
   unbiased, uncaring, unconcerned, undazzled, undiscriminating,
   uninfluenced, uninquiring, uninterested, uninvolved, unjaundiced,
   unmindful, unpossessive, unprejudiced, unprepossessed,
   unpretentious, unselfish, unsolicitous, unsparing of self,
   unswayed, withdrawn