Stable
Steady
Synonyms Firm, steady, fixed, fast, sturdy, moored, stuck down, well built, substantial, solid, secure, strong, stout, safe, anchored, immovable, and well constructed.
Sound
Synonyms Well balanced, sound, of sound mind, normal, able to think/reason clearly, clear-headed, coherent, reasonable, sober, matter-of-fact, all there, balanced, mentally sound, sane, right in the head, lucid, rational, steady, sensible, down-to-earth, and compos mentis.
Solid
Synonyms Secure, strong, firm, steadfast, unwavering, unfaltering, unswerving, long-lasting, deep-rooted, well grounded, durable, lasting, permanent, dependable, solid, steady, sure, level, unvarying, unfluctuating, established, long-lived, well founded, abiding, enduring, constant, reliable, and true.
Example Sentences
The horse rested inside stable stalls.
She maintained a stable job throughout.
Their relationship remained stable and strong.
The building foundation felt stable today.