| stiff(adjective, hard, tough, firm, rigid) |
| arthritic(adjective, hard, firm, solid, stiff) |
| buckram(adjective, hard, firm, solid, stiff) |
| creaky(adjective, hard, firm, solid, stiff) |
| inductile(adjective, rigid, inflexible) |
| inelastic(adjective, hard, tough, firm, solid) |
| inextensible(adjective, rigid, inflexible) |
| inflexible(adjective, hard, tough, firm, solid) |
| intractable(adjective, tough, firm, fixed, distant) |
| rigid(adjective, hard, tough, firm, solid) |
| steely(adjective, hard, firm, solid, stiff) |
| stiff as a board(expression, idiom, firm, solid, stiff) |
| unbending(adjective, hard, firm, solid, rigid) |
| unsupple(adjective, hard, firm, solid, stiff) |
| unyielding(adjective, hard, tough, firm, solid) |
| adamant |
| annealed(adjective, hard, firm, solid, tense) |
| benumbed(adjective, hard, firm, solid, tense) |
| brittle(adjective, hard, firm, solid, tense) |
| cemented(adjective, hard, firm, solid, tense) |