| firm(adjective, mean, hard, tough, harsh) |
| fixed(adjective, mean, hard, tough, harsh) |
| flat(adjective, cool, detached, blank, sober) |
| forbidding(adjective, indifferent, detached, distant, remote) |
| frigid(adjective, cool, detached, blank, sober) |
| glacial(adjective, cool, detached, blank, sober) |
| hanging tough(expression, adjective, mean, hard, stubborn) |
| hard(adjective, mean, tough, severe, cruel) |
| hard-nosed(adjective, mean, hard, tough, harsh) |
| hard as nails(expression, adjective, idiom, tough, harsh) |
| hardened(adjective, hard, tough, severe, cruel) |
| harsh(adjective, mean, hard, tough, cruel) |
| haughty(adjective, indifferent, detached, distant, remote) |
| icy(adjective, hard, cool, tough, severe) |
| immovable(adjective, mean, hard, cool, flat) |
| impassive(adjective, calm, cool, restrained, detached) |
| impersonal(adjective, cool, detached, blank, sober) |
| impervious(adjective, calm, restrained, unconcerned, subdued) |
| implacable(adjective, mean, hard, tough, harsh) |
| in cold blood(expression, adjective, idiom, cool, flat) |