| sustaining(verb, adjective, increase, line, current) |
| undying(adjective, continuous, permanent, recurrent, perpetual) |
| interminable(adjective, continuous, endless, unrelenting, never-ending) |
| long-lived(adjective, continue, familiar, persistent, established) |
| maintaining(verb, adjective, increase, line, current) |
| remaining(verb, adjective, split, persistent, extra) |
| fixed(adjective, established, hardened, unaffected, lasting) |
| incessant(adjective, strong, firm, determined, steady) |
| inveterate(adjective, familiar, fixed, persistent, established) |
| long-lasting(adjective, continue, familiar, established, hardened) |
| long-standing(adjective, continue, persistent, continuous, hardened) |
| progressive(adjective, liberal, growing, on-going) |
| staying(verb, split, familiar, extra, established) |
| steady(adjective, strong, firm, slow, determined) |
| unceasing(adjective, strong, firm, determined, steady) |
| eternal(adjective, certain, stable, fixed, persistent) |
| everlasting(adjective, continuous, endless, enduring, unrelenting) |
| existing(verb, adjective, active, living, established) |
| lifelong(adjective, familiar, fixed, persistent, lasting) |
| lingering(verb, adjective, continue, fixed, persistent) |