be stuck for something
From Longman Dictionary of Contemporary Englishbe stuck for somethingbe stuck for somethingto be unable to think what to say or do For once Anthony was stuck for words (=did not know what to say). → stuckExamples from the Corpusbe stuck for something• Most of what they accused him of was true, and Wyden was stuck for an answer.• I was stuck for an answer.• Antony for once was stuck for words.