| mechanical(adjective, robotic) |
| relaxed(adjective, calm, quiet, cool, moderate) |
| retiring(adjective, calm, controlled, self-possessed) |
| self-contained(adjective, cool, blank, aloof, serene) |
| self-controlled(adjective, calm, quiet, cool, relaxed) |
| sluggish(adjective, calm, dull, flat, unfeeling) |
| soulless(adjective, hard, unfeeling, unsympathetic, impassive) |
| standoffish(adjective, indifferent, restrained, hostile, unfriendly) |
| steely(adjective, cold, cruel, hostile, unfriendly) |
| unstirred(adjective, mean, hard, cold, indifferent) |
| adamant(adjective, mean, hard, harsh, cold) |
| affectless |
| blah(adjective, calm, dull, flat, informal) |
| casual(adjective, calm, cool, relaxed, indifferent) |
| cold fish(expression, adjective, mean, hard, cool) |
| coolheaded(adjective, calm, quiet, cool, relaxed) |
| cruel(adjective, mean, hard, cool, tough) |
| deadpan(adjective, calm, dull, cool, tough) |
| easygoing(adjective, calm, cool, relaxed, casual) |
| feeble |