Third-person singular simple present indicative form of gnash.(verb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "gnashes" in a sentence
"* Mitt Romney's Gordian Knot, ctd: Mitt gnashes teeth as GOP Rep Paul Ryan opines that Romneycare is "not that dissimilar to Obamacare," another sign that he'll remain a nonstarter in the 2012 GOP primary until he repudiates what used to be seen as a middle-of-the-road policy solution before Obama adopted the mandate."
"It includes some eerie elements, like a massive Mouse King puppet that gnashes its teeth, prompting occasional wails of "Mommy!" from the young audience."
"In this "Nutcracker," a Wild Thing hides in the scenery and a massive Mouse King puppet gnashes its teeth, prompting screams from some children in the audience."