Pocket Thesaurus
Antonyms of impregnable
uncompromising, stubborn, resolute, determined, intransigent, insistent, rigid, firm, immovable, set, pat, stiff, fixed, hard-nosed, inexorable, inflexible, obdurate, relentless, unbending, unrelenting, unshakable, unbendable, hanging tough, set in stone, standing pat, unswayable
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