| starched(verb, adjective, hard, firm, solid) |
| starchy(adjective, hard, firm, solid, tense) |
| stark(adjective, hard, firm, solid, tense) |
| static(adjective, dull, idle, even, sluggish) |
| steeled |
| steely(adjective, hard, firm, solid, tense) |
| stern(adjective, determined, resolute, uncompromising, unshakeable) |
| stiff as a board(expression, adjective, idiom, firm, solid) |
| still(dull, idle, sluggish, lazy, motionless) |
| stony(adjective, hard, firm, solid, stiff) |
| straight(adjective, even, rigid, inflexible, reliable) |
| strengthened |
| symmetrical(adjective, normal, even, rigid, inflexible) |
| syrupy(adjective, set, solid, heavy, deep) |
| systematic(adjective, even, rigid, inflexible, reliable) |
| taut(adjective, hard, firm, solid, stiff) |
| tense(adjective, hard, firm, solid, stiff) |
| tight(adjective, hard, firm, solid, stiff) |
| torpid(dull, sluggish, lazy, motionless, unmoving) |
| toughened |