From Longman Dictionary of Contemporary Englishcry wolfcry wolfLIE/TELL A LIEto ask for help when you do not need it, so that people do not believe you when you really need help → cry
Examples from the Corpus
cry wolf• A weather forecaster who cried wolf led to the cancellation of the club's picnic.• The growers who are crying wolf today about the lack of water will post their annual profits in a few months.• One does not cry wolf with panic buttons. 