| tough(adjective, calm, strong, sound, fit) |
| unchanged(fixed, static, unchangeable) |
| vintage(adjective, familiar, established, antique, old-time) |
| accepting |
| ageless(adjective, fixed, unchanging, permanent, static) |
| classic |
| determined(adjective, strong, flat, warm, firm) |
| dogged(adjective, tenacious) |
| existing(verb, adjective, present, living, alive) |
| forbearing(adjective, calm, quiet, gentle, flat) |
| fresh(strong, fit, healthy, well, robust) |
| indelible(adjective, great, extraordinary, outstanding, notable) |
| indissoluble(adjective, permanent, everlasting, eternal, remaining) |
| insistent(adjective, tenacious) |
| living(verb, adjective, present, living, alive) |
| monumental(adjective, great, extraordinary, outstanding, remarkable) |
| obstinate(adjective, determined, resolute, persistent, hardened) |
| passive(adjective, quiet, gentle, tolerant, lifeless) |
| prevailing(verb, adjective, strong, certain, definite) |
| stubborn(adjective, set, firm, determined, resolute) |