modified
indifferent, careless, feckless, heedless, apathetic, insensible, oblivious, nonchalant, insouciant, inattentive, cold, phlegmatic, impassive, supine, callous, unsympathetic, hardened, insensitive, stony, neutral, reserved, self-centered, negligent, blind, deaf, forgetful, disdainful, lukewarm, cool, lackadaisical, uninterested.
Antonyms interested*, absorbed, attached. See syn. study at indifferent.indifferent.