| inbred(adjective, complete, natural, fixed, established) |
| incurable(adjective, fixed, persistent, established, hardened) |
| ineradicable(adjective, set, continue, fixed, established) |
| innate(adjective, established) |
| lasting(adjective, fixed, persistent, recurrent, perpetual) |
| long-lived(adjective, familiar, persistent, established, hardened) |
| obstinate(adjective, firm, determined, usual, regular) |
| customary(adjective, firm, determined, usual, regular) |
| abiding(adjective, certain, limited, definite, persistent) |
| lifelong(adjective, familiar, fixed, persistent, established) |
| perpetual(adjective, familiar, usual, established, hardened) |
| usual(adjective, determined, regular, routine, normal) |
| accustomed(adjective, established) |
| addicted(adjective, established) |
| constant(familiar, usual, fixed, persistent, established) |
| firm(adjective, certain, familiar, usual, limited) |
| long-lasting(adjective, familiar, established, hardened, confirmed) |
| long-standing(adjective, persistent, continuous, hardened, lasting) |
| steadfast(adjective, certain, determined, usual, regular) |
| steady(adjective, certain, familiar, usual, regular) |