| chilled(adjective, hard, firm, solid, tense) |
| congealed(adjective, hard, firm, solid, tense) |
| contracted(adjective, hard, firm, solid, tense) |
| crisp(adjective, tough, firm, fixed, distant) |
| distant(adjective, tough, firm, fixed, rigid) |
| do or die(expression, adjective, idiom, tough, firm) |
| dug in(expression, adjective, tough, firm, distant) |
| firm(adjective, hard, tough, solid, rigid) |
| fixed(adjective, hard, firm, solid, rigid) |
| formal(adjective, tough, firm, fixed, distant) |
| frozen(adjective, hard, firm, solid, tense) |
| graceless(adjective, hard, firm, solid, tense) |
| hard(adjective, firm, solid, stiff, rigid) |
| hard as nails(expression, adjective, idiom, tough, firm) |
| hardened(adjective, hard, firm, solid, stiff) |
| hold the fort(expression, adjective, idiom, tough, firm) |
| hold the line(expression, adjective, idiom, tough, firm) |
| immalleable(adjective, hard, firm, solid, stiff) |
| immovable |
| immutable |