foul ball . foul ball {n.} A batted baseball that lands outside the foul line. Mickey hit a long foul ball that landed on the roof. Categories: add yours {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: F Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Add my comment