verb (used with object)

to grind or strike (the teeth) together, especially in rage or pain.
to bite with grinding teeth.

verb (used without object)

to gnash the teeth.


an act of gnashing.

Origin of gnash

1490–1500; variant of obsolete gnast, Middle English gnasten; compare Old Norse gnastan gnashing of teeth
Related formsgnash·ing·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for gnash

grate, crush, clamp, rub, grit

Examples from the Web for gnash

Historical Examples of gnash

  • Then she would stare at the child and gnash her teeth as though with hate.

    Allan's Wife

    H. Rider Haggard

  • Men and women will gnash their teeth against their own children.

    Modern Persia

    Mooshie G. Daniel

  • Coming back in the cars, I had a rencontre that makes me gnash my teeth yet.

    A Confederate Girl's Diary

    Sarah Margan Dawson

  • With them I can with one gnash divide a knight in half at the waist.

    The Days of Chivalry

    Ernest Louis Victor Jules L'Epine

  • He did so; Jeanne hearkened; and then it was Sweder's turn to gnash his teeth.

    The Story of Brussels

    Ernest Gilliat-Smith

British Dictionary definitions for gnash



to grind (the teeth) together, as in pain or anger
(tr) to bite or chew as by grinding the teeth


the act of gnashing the teeth
Derived Formsgnashingly, adverb

Word Origin for gnash

C15: probably of Scandinavian origin; compare Old Norse gnastan gnashing of teeth, gnesta to clatter
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 gnash

early 15c., variant of Middle English gnasten "to gnash the teeth" (c.1300), perhaps from Old Norse gnastan "a gnashing," of unknown origin, probably imitative. Cf. German knistern "to crackle." Related: Gnashed; gnashing.

Online Etymology Dictionary, © 2010 Douglas Harper