horse opera . horse opera {n. phr.} A Western movie in which cowboys and horses play a major part. John Wayne played in many horse operas. Categories: add yours {n. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: H Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Post my comment