[pen-i-truh nt]


a person or thing that penetrates.
a compound that penetrates the skin, as a lotion or cream.
a substance that lowers the surface tension of water; wetting agent.
Zoology. a large nematocyst discharging a barbed thread that penetrates the body of the prey and injects a toxic fluid.


Origin of penetrant

1535–45; < Latin penetrant- (stem of penetrāns), present participle of penetrāre to penetrate; see -ant
Related formsun·pen·e·trant, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for penetrant

Historical Examples of penetrant

  • Then he raised his eyes from the water and swept the sky in a penetrant gaze.

    The Harvester

    Gene Stratton Porter

  • "What he doesn't sell he buys," he cried in his nervous, penetrant tones.

  • With Mr. Tassers penetrant and suspicious gaze on him, he decided that it would be wise to avoid all seeming interest in Myron.

    Full-Back Foster

    Ralph Henry Barbour

  • The dew lay heavy on the laurel leaves of the thickets, and the breeze was perfumed with the penetrant fragrance of many blossoms.

  • Sharp shoe-calks afford a means of infliction of penetrant wounds which may occasion open joint and infectious arthritis.

    Lameness of the Horse

    John Victor Lacroix

British Dictionary definitions for penetrant



sharp; penetrating


chem a substance that lowers the surface tension of a liquid and thus causes it to penetrate or be absorbed more easily
a person or thing that penetrates
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