| stabile(adjective, firm, solid, stable, fixed) |
| stable(adjective, firm, solid, fixed, sturdy) |
| staunch(adjective, firm, sensible, solid, steady) |
| steadfast(adjective, firm, sensible, solid, steady) |
| steady-going(adjective, firm, solid, stable, fixed) |
| sturdy(adjective, firm, solid, stable, fixed) |
| substantial(adjective, firm, solid, stable, fixed) |
| sure(adjective, firm, solid, stable, fixed) |
| unchangeable(adjective, firm, solid, stable, fixed) |
| unchanging(adjective, firm, solid, stable, fixed) |
| unfaltering(adjective, firm, solid, stable, fixed) |
| unfluctuating(adjective, firm, solid, stable, fixed) |
| uniform(adjective, firm, solid, stable, fixed) |
| unqualified(adjective, firm, solid, stable, fixed) |
| unquestioning(adjective, firm, solid, stable, fixed) |
| unshaken(adjective, firm, solid, stable, fixed) |
| unswerving(adjective, firm, sensible, solid, steady) |
| unvarying(adjective, firm, solid, stable, fixed) |
| unwavering(adjective, firm, sensible, solid, steady) |
| wholehearted(adjective, firm, sensible, solid, steady) |