| inflexible(adjective, set, certain, limited, definite) |
| irrevocable(adjective, certain, fixed, unquestionable, permanent) |
| resolute(adjective, firm, solid, stable, fixed) |
| sure(adjective, clear, firm, solid, certain) |
| unending |
| unremitting |
| ceaseless |
| endless |
| equable(adjective, smooth, right, firm, solid) |
| even(adjective, smooth, right, firm, solid) |
| immobile(adjective, intense, still, fixed, resolute) |
| settled(adjective, firm, solid, certain, stable) |
| unaltered(adjective, uniform, unchanging, unchanged) |
| undeviating(adjective, severe, harsh, solid, certain) |
| unfaltering(adjective, clear, firm, solid, certain) |
| unshakable(adjective, clear, certain, definite, unquestionable) |
| unwavering(adjective, clear, firm, solid, certain) |
| certain(adjective, firm, solid, stable, limited) |
| continuing(fixed, static, unvarying, unchangeable, unalterable) |
| continuous(adjective, stable) |