grindstone UK /ˈɡɹaɪn(d)ˌstəʊn/US /ˈɡɹaɪn(d)ˌstoʊn/noun 2forms 1phrases 1 noun2 •An abrasive wheel for sharpening, polishing, or grinding. •Synonym of starry flounder. formsgrindstones Phrases with grindstone nose to the grindstoneUsed to form idioms meaning "to force oneself to work hard or to focus intensely upon one's work".
