uncaring

boorish, heedless, inconsiderate, thoughtless, unfriendly, unloving, unthinking

affectless, callous, case-hardened, cold-blooded, compassionless, desensitized, hard, hard-boiled, hard-hearted, heartless, indurate, inhuman, inhumane, insensate, insensitive, ironhearted, merciless, obdurate, pachydermatous, pitiless, remorseless, ruthless, slash-and-burn, soulless, stony (also stoney), stonyhearted, take-no-prisoners, thick-skinned, uncharitable, unfeeling, unmerciful, unsparing, unsympathetic

apathetic, disinterested, dispassionate, emotionless, impassive, indifferent, neutral, uninterested

lackadaisical, languid, listless, perfunctory, undemonstrative, unemotional, unresponsive

unfeeling, unsympathetic

halfhearted, lukewarm, tepid, uneager, unenthusiastic

austere, cold, frosty