| invariable(adjective, certain, fixed, reliable, continuous) |
| left of center(expression, adjective, idiom, tolerant, modern) |
| loyal |
| never-ending(adjective, persistent, constant, endless, unrelenting) |
| normal |
| obstinate(persistent, continuous, hardened, lasting, confirmed) |
| occurring(verb, existing) |
| of long duration(expression, idiom) |
| of long standing(expression, idiom, familiar, established, long-established) |
| patient(adjective, strong, firm, determined, steady) |
| periodic(adjective, regular, scheduled, once-a-month) |
| persistence(noun, strength, ability, resolution, capacity) |
| pertinacious(adjective, strong, firm, determined, steady) |
| plodding(adjective, strong, firm, slow, determined) |
| plugging(adjective, strong, firm, determined, steady) |
| prevailing(verb, existing) |
| prolonged(adjective, continue, persistent, lasting, remaining) |
| prosecuting |
| residing(verb, living) |
| resolute(adjective, strong, firm, wild, determined) |