look out for look out for {v. phr.} To watch out for; be on the alert. There were signs along the highway warning drivers to look out for deer crossing. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: L Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry