- not penetrable; that cannot be penetrated, pierced, entered, etc.
- inaccessible to ideas, influences, etc.
- incapable of being understood; inscrutable; unfathomable: an impenetrable mystery.
- Physics. possessing impenetrability.
Origin of impenetrable
SynonymsSee more synonyms on Thesaurus.com
3. incomprehensible, mysterious, obscure, hidden.
3. clear, lucid.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for impenetrable
At the highest navigable point of the Congo River, thick jungle creates an impenetrable wall of green around a large island.The Congo's Forgotten Colonial Getaway
December 18, 2014
These reporters are working within a bubble, impenetrable to secular outsiders.Who Gagged the Search for MH370?
June 22, 2014
But, as Korda clearly recognizes, Lee himself could be almost as impenetrable as stone.How I Learned to Hate Robert E. Lee
June 22, 2014
The Brazilian defense, touted as impenetrable in pre-tournament hype, proved to be bedraggled, and porous.Brazil Slips Past Croatia, Thanks to Yuichi Nishimura
June 12, 2014
He had two hits for three official at-bats; yet afterward his solitary gloom was impenetrable.Murray Kempton on The Homecoming of Willie Mays
March 31, 2014
“An impenetrable mystery” was sure “to hang for ever” as far as all mankind was concerned.The Secret Agent
Kirkwood smiled grimly, with a face of brass, impenetrable, inflexible.The Black Bag
Louis Joseph Vance
Go not to the Alhambra: the fort is impenetrable—the guard faithful.Leila, Complete
He had been prepared for abuse, but not for impenetrable silence.One Day's Courtship
Since then Tawabinisy had hidden himself behind his impenetrable grin.The Forest
Stewart Edward White
- incapable of being pierced through or penetratedan impenetrable forest
- incapable of being understood; incomprehensibleimpenetrable jargon
- incapable of being seen throughimpenetrable gloom
- not susceptible to ideas, influence, etcimpenetrable ignorance
- physics (of a body) incapable of occupying the same space as another body
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 impenetrable
Online Etymology Dictionary, © 2010 Douglas Harper