Synonyms: unassailable, bulletproof, unshakable, watertight
Definition: without flaws or loopholes
Usage: an ironclad contract; a watertight alibi; a bulletproof argument
Similar words: incontestable, incontestible
Definition: incapable of being contested or disputed
Synonyms: unbendable, unfaltering, steadfast, steady, stiff, unshakable, unwavering, firm
Definition: marked by firm determination or resolution; not shakable
Usage: firm convictions; a firm mouth; steadfast resolve; a man of unbendable perseverence; unwavering loyalty
Similar words: resolute
Definition: firm in purpose or belief; characterized by firmness and determination
Usage: stood resolute against the enemy; faced with a resolute opposition; a resolute and unshakeable faith