• synonyms


See more synonyms for impregnable on Thesaurus.com
  1. strong enough to resist or withstand attack; not to be taken by force, unconquerable: an impregnable fort.
  2. not to be overcome or overthrown: an impregnable argument.
Show More

Origin of impregnable1

1400–50; late Middle English impregnable, imprenable < Middle French, equivalent to im- im-2 + prenable pregnable
Related formsim·preg·na·bil·i·ty, im·preg·na·ble·ness, nounim·preg·na·bly, adverb


See more synonyms for on Thesaurus.com
1. invulnerable. 1, 2. See invincible. 2. unassailable.


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words


Examples from the Web for impregnability

Contemporary Examples

Historical Examples

  • If any spot can impress the notion of impregnability it is Kuffstein.

  • Of course his impregnability gave rise to all manner of stories.

    The New Tenant

    E. Phillips Oppenheim

  • But its impregnability could not offset its gross imprudence.

    Benjamin Franklin

    John Torrey Morse, Jr.

  • These were old and had not been repaired, since the Saguntines trusted in the impregnability of the steeps.


    Vicente Blasco Ibez

  • If any spot can impress the notion of impregnability, it is Kuffstein.

British Dictionary definitions for impregnability


  1. unable to be broken into or taken by forcean impregnable castle
  2. unable to be shaken or overcomeimpregnable self-confidence
  3. incapable of being refutedan impregnable argument
Show More
Derived Formsimpregnability or impregnableness, nounimpregnably, adverb

Word Origin

C15 imprenable, from Old French, from im- (not) + prenable able to be taken, from prendre to take


impregnatable (ˌɪmprɛɡˈneɪtəbəl)

  1. able to be impregnated; fertile
Show More
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for impregnability



early 15c., imprenable "impossible to capture," from Middle French imprenable "invulnerable," from assimilated form of in- "not, opposite of" (see in- (1)) + Old French prenable "assailable, vulnerable" (see pregnable). With intrusive -g- 16c., on model of deign, reign, etc. Related: Impregnability.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper