<p><strong>Noun:</strong></p><ul><li>a gross, stupid, or careless mistake: That's your second blunder this morning.</li><li>Synonyms: error</li></ul><p><strong>Verb (used without object):</strong></p><ul><li>to move or act blindly, stupidly, or without direction or steady guidance: Without my glasses I blundered into the wrong room.</li><li>to make a gross or stupid mistake, especially through carelessness or mental confusion: Just pray that he doesn't blunder again and get the names wrong.</li></ul><p><strong>Verb (used with object):</strong></p><ul><li>to bungle; botch: Several of the accounts were blundered by that new assistant.</li><li>to utter thoughtlessly; blurt out: He blundered his surprise at their winning the award.</li></ul>