unbreakable Synonyms

uninjectable unyielding unshakable undestroyable unavoided tough tight sturdy strong stony stiff steely stable unalterable steel-plated unexchangeable undecryptable undeciphered splinterless shatterproof rocklike rock hard nonbreaking nonbreakable reinforced long-lasting hardest splinterproof solid rugged impenetrable hardened hard flinty fixed firm everlasting eternal durable binding armored adamantine imperishable indestructible rocky rigid resistant lasting iron invulnerable