impenetrable

alternative inpenetrable

1. not comparableNot penetrable.

   The fortress is impenetrable, so it cannot be taken.

   1 more example

   The avalanche spread and stopped, locking everything it carried into an icy cocoon. It was now a jagged, virtually impenetrable pile of ice, longer than a football field and nearly as wide.

   2012, John Branch, “Snow fall: The avalanche at Tunnel Creek”, in The New York Times, New York, N.Y.: The New York Times Company, →ISSN, →OCLC, archived from the original on 11 Jun 2024

   Synonyms: impermeable, impregnable · Antonyms: penetrable, permeable, pregnable

2. not comparableOpaque; obscure; not translucent or transparent.

   When night falls, she cloaks the world in impenetrable darkness.

   1991, Varg Vikernes, “Dunkelheit”, performed by Burzum

3. figurativelynot comparableIncomprehensible; fathomless; inscrutable.

   Business jargon makes this document impenetrable—I can’t understand it.

   Synonyms: unfathomable, abstruse, Chinese, dense, enigmatic, fathomless, bottomless, Greek · Antonyms: fathomable, apprehensible, clear, limpid, comprehensible, explainable, explicable, explicatable

plural impenetrables · alternative inpenetrable

1. A person not openly given to friendship.

   I should lose the reputation that I am gradually acquiring among our impenetrables here, were I to confess the excitement which I felt at the idea of entering his house—the house of that great general under whose command you made your first charge.

   1837, L[etitia] E[lizabeth] L[andon], “Chapter XXVI. Lady Marchmont to Sir Jasper Meredith.”, in Ethel Churchill: Or, The Two Brides. […], volume I, London: Henry Colburn, […], →OCLC, page 236