| unyielding(adjective, hard, tough, firm) |
| hardened(verb, adjective, strong, hard) |
| impermeable(adjective, hard, tough, firm) |
| stony(adjective, strong, hard, firm) |
| substantial(adjective, close, strong, hard) |
| tough(adjective, hard, firm, solid) |
| caked(adjective, firm, solid, heavy) |
| calcified(adjective, firm, solid, hardened) |
| callous(adjective, strong, hard, firm) |
| cemented(adjective, firm, solid, hardened) |
| clabbered(adjective, solid, heavy, deep) |
| close-grained(adjective, hard, tough, firm) |
| clotted(adjective, solid, heavy, deep) |
| coagulated(adjective, solid, heavy, deep) |
| congealed(adjective, hard, tough, firm) |
| conglomerated(verb, adjective, firm, solid) |
| curdled(adjective, solid, heavy, deep) |
| deep(adjective, solid, heavy, stiff) |
| dried(adjective, firm, solid, hardened) |
| fixed(verb, adjective, slight, fine) |