| pertinacious |
| recurrent(adjective, persistent, continuous, everlasting, uninterrupted) |
| reliable(adjective, calm, strong, tough, solid) |
| resolute(calm, strong, firm, solid, true) |
| rooted(adjective, persistent, remaining) |
| secure(calm, strong, firm, solid, true) |
| sempervirent |
| set(adjective, calm, strong, firm, solid) |
| solid(calm, strong, certain, steady, substantial) |
| static(fixed, unchangeable) |
| stretched out(expression, vast, extended, lingering, prolonged) |
| stringy(adjective, great, deep, high, remote) |
| subsisting(verb, existing) |
| suffering(verb, abiding) |
| tolerating(verb, abiding) |
| unabating(persistent, remaining) |
| unbreakable(adjective, strong, tough) |
| unbroken(adjective, persistent, constant, continuous, endless) |
| unfailing(certain, fixed, reliable, continuous, trustworthy) |
| unforgettable(adjective, great, extraordinary, outstanding, remarkable) |