| long-lasting(adjective, tough, continue, familiar, sturdy) |
| patient(adjective, calm, quiet, cool, gentle) |
| chronic(adjective, fixed, persistent, constant, current) |
| long-suffering(adjective, calm, quiet, cool, gentle) |
| remaining(verb, adjective, outstanding, persistent, current) |
| resolute(adjective, calm, close, strong, secure) |
| tenacious(adjective, strong, sound, tough, fit) |
| unceasing(adjective, steady, stable, persistent, constant) |
| unchangeable(adjective, calm, strong, secure, flat) |
| unqualified(adjective, strong, complete, flat, firm) |
| continual(adjective, certain, determined, stable, persistent) |
| faithful(adjective, close, correct, firm, certain) |
| indefatigable(adjective, set, strong, fit, healthy) |
| indomitable(adjective, calm, cool, determined, resolute) |
| long(adjective, time, great, deep, high) |
| long-term(adjective, lasting, permanent, lifelong) |
| timeless(adjective, eternal) |
| tolerating(verb, abiding) |
| unflagging(adjective, set, strong, steady, constant) |
| uninterrupted(adjective, steady, persistent, constant, monotonous) |