| cemented(adjective, set, firm, solid, hardened) |
| certain(adjective, firm, solid, determined, usual) |
| changeless(adjective, set, severe, firm, harsh) |
| cold fish(expression, adjective, mean, hard, unfeeling) |
| compact(adjective, set, firm, solid, hardened) |
| compressed(adjective, set, firm, solid, hardened) |
| concluded(adjective, firm, determined, usual, regular) |
| concrete(adjective, set, firm, stiff, hardened) |
| concreted |
| confirmed(adjective, firm, determined, usual, regular) |
| congealed(adjective, set, firm, solid, hardened) |
| conglomerated(adjective, set, firm, solid, stiff) |
| consolidated(adjective, set, firm, solid, hardened) |
| constant(adjective, calm, strong, secure, firm) |
| continual(adjective, stable, constant, enduring, lasting) |
| contrary(adjective, determined, resolute, obstinate, uncompromising) |
| crisp(adjective, tough, firm, fixed, distant) |
| customary(adjective, firm, determined, usual, regular) |
| decided(adjective, firm, determined, usual, regular) |
| decisive(adjective, firm, determined, usual, regular) |