| indissoluble(adjective, strong, enduring, permanent, everlasting) |
| long-lasting(adjective, tough, continue, sturdy, constant) |
| persisting(verb, adjective, persistent, current, old) |
| changeless(adjective, stable, fixed, constant, enduring) |
| incessant(adjective, persistent, constant, continuous, endless) |
| loyal(firm, certain, true, fixed, constant) |
| perdurable(adjective, calm, strong, tough, continue) |
| persevering(verb, adjective, persevering, abiding) |
| remaining(verb, adjective, outstanding, persistent, current) |
| unvarying(adjective, calm, strong, secure, firm) |
| long-term(adjective, vast, permanent, lifelong, diurnal) |
| extended(adjective, extensive, expanded, lingering, prolonged) |
| faithful(firm, certain, true, fixed, constant) |
| inveterate(adjective, fixed, persistent, recurrent, perpetual) |
| lifelong(adjective, fixed, persistent, permanent, durable) |
| old(adjective, continue, permanent, recurrent, perpetual) |
| prolonged(adjective, great, deep, high, persistent) |
| timeless(adjective, vast, permanent, everlasting, eternal) |
| uninterrupted(adjective, persistent, constant, continuous, endless) |
| unremitting(adjective, persistent, constant, living, continuous) |