| irretrievable |
| stated(strong, certain, definite, fixed, rigid) |
| tough(adjective, calm, strong, rough, solid) |
| unaltered(adjective, stability) |
| unavoidable(adjective, expected, predictable, necessary, inexorable) |
| unbending(set, strong, hard, severe, definite) |
| unmodifiable(adjective, set, secure, steady, fixed) |
| definite(adjective, strong, severe, certain, fixed) |
| dogged(adjective, hard, determined, fixed, inflexible) |
| everlasting(adjective, fixed, persistent, continuous, endless) |
| incommutable |
| inconvertible |
| incorrigible(adjective, complete, even, rigid, absolute) |
| indestructible(adjective, unable, lasting) |
| invariant |
| level(adjective, even, rigid, inflexible, reliable) |
| obdurate(adjective, severe, definite, fixed, stiff) |
| relentless(adjective, close, set, hard, severe) |
| resolved(adjective, strong, certain, determined, definite) |
| strict(set, strong, hard, severe, certain) |