Synonyms of unbreakable

1 Syllable
firm, tough, tight
2 Syllables
rugged, tougher, rigid, brass-bound, toughest, solid, lasting
3 Syllables
unyielding, durable, toughened, armored, resistant, steel-plated, shatterproof, unfading
4 Syllables
unshakable, infrangible, nonbreakable, everlasting, perdurable
5 Syllables
irrefragable, irrefrangible, adamantine, nonperishable, incorruptible, unpermissive, indestructible, invulnerable, indivisible
6 Syllables
inexterminable