Synonyms and Antonyms of impregnable

  1. 1 incapable of being defeated, overcome, or subdued <an impregnable fortress that had foiled one invader after another over the centuries> Synonyms bulletproof, invincible, indomitable, insuperable, insurmountable, invulnerable, unbeatable, unconquerable, unstoppableRelated Words inviolable, unassailable, unbreachable, untouchable; armored, defended, guarded, protected, safe, safeguarded, secure, shielded; unbeaten, unbowed, unconquered, undefeated, unsubduedNear Antonyms exposed, imperiled (or imperilled), insecure, liable, open, susceptible, unguarded, unprotected, unsafe; defenseless, helpless, powerless, weakAntonyms superable, surmountable, vincible, vulnerable

  2. 2 impossible to get through or into <the castle's supposedly impregnable walls> Synonyms impassable (also impassible), impermeable, impervious, impenetrableRelated Words close, compact, dense, thick, tight; compressed, condensed; sturdy, substantial, tough; firm, frozen, hard, solid, stiff; inflexible, rigid, unbending, unyieldingNear Antonyms soft, squishy; bendable, elastic, flexible, giving, malleable, pliable, yielding; absorbent, porousAntonyms negotiable, passable, penetrable, permeable

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