bird has flown bird has flown {slang} The prisoner has escaped; the captive has got away. When the sheriff returned to the jail, he discovered that the bird had flown. Categories: add yours {slang} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: B Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry