Same word as in-hospitable:

apathetic, cold-blooded, cool, dead, distant, emotionless, frigid, frosty, glacial, icy, impersonal, imperturbable, indifferent, inhibited, inhospitable, joyless, lukewarm, matter-of-fact, passionless, phlegmatic, reserved, reticent, spiritless, standoffish, stony, u