adj. 25B6; adjective CARELESS, lazy, lax, unenthusiastic, half-hearted, lukewarm, indifferent, unconcerned, casual, offhand, blasé, insouciant, relaxed; apathetic, lethargic, listless, sluggish, spiritless, passionless; informal laid-back, couldn't-care-less, easy going.
enthusiastic.