Same word as in-excitable:
apathetic, callous, cold, cold-blooded, collected, composed, dispassionate, dry, emotionless, hardened, heartless, imperturbable, indifferent, indurated, inexcitable, inexpressive, inscrutable, insensible, insusceptible, matter-of-fact, nonchalant, passionless, phleg
apathetic, callous, cold, cold-blooded, collected, composed, dispassionate, dry, emotionless, hardened, heartless, imperturbable, indifferent, indurated, inexcitable, inexpressive, inscrutable, insensible, insusceptible, matter-of-fact, nonchalant, passionless, phleg