| well-established(adjective, strain, firmness, labour, hardiness) |
| withstanding(adjective, strength, strain, ability, resolution) |
| continuing(noun, verb, adjective, increase, strength) |
| immutable(adjective, calm, strong, secure, firm) |
| persevering(verb, adjective, quiet, set, strong) |
| immortal(adjective, constant, abundant, supreme, unfathomable) |
| persisting(noun, verb, adjective, increase, line) |
| unchanging(adjective, close, correct, firm, honest) |
| indestructible(adjective, tough, stable, sturdy, constant) |
| perennial(adjective, continue, stable, constant, lasting) |
| stoic(adjective, cool, tolerant, unemotional, submissive) |
| undying(adjective, constant, endless, lasting, infinite) |
| unwavering(adjective, calm, close, strong, secure) |
| changeless(adjective, firm, solid, certain, stable) |
| endless(adjective, certain, determined, steady, stable) |
| imperishable(adjective, fixed, constant, lasting, durable) |
| long-lived(adjective, continue, familiar, established, hardened) |
| unending(adjective, steady, stable, persistent, constant) |
| unfaltering(adjective, complete, firm, total, solid) |
| ceaseless(adjective, certain, steady, persistent, constant) |