prey on one's mind prey on one's mind {v. phr.} To afflict; worry. He couldn't sleep because his many debts were preying on his mind. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: P Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Leave my opinion