| stout(calm, strong, tough, solid, substantial) |
| strong(calm, tough, solid, steady, substantial) |
| sturdy(calm, strong, tough, solid, steady) |
| substantial(calm, strong, tough, solid, steady) |
| sure(calm, strong, solid, steady, substantial) |
| termless(lasting, permanent, everlasting, unending, undying) |
| till the cows come home(expression, idiom, permanent, long-term, lifelong) |
| together(calm, strong, solid, steady, substantial) |
| unalterable(calm, strong, solid, steady, substantial) |
| unchangeable(calm, strong, solid, steady, substantial) |
| unchanging(steady, stable, even, constant, enduring) |
| unfluctuating(calm, strong, solid, steady, substantial) |
| uniform(calm, strong, solid, steady, substantial) |
| unintermitting |
| uninterrupted |
| unvarying(calm, strong, solid, steady, substantial) |
| unwavering(calm, strong, solid, steady, substantial) |
| vital |
| well-built(calm, strong, solid, steady, substantial) |
| well-founded(calm, strong, solid, steady, substantial) |