holy terror . holy terror {n.}, {informal} A very disobedient or unruly child; brat. All the children are afraid of Johnny because he's a holy terror. Categories: add yours children {informal} {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 » In RussianTo section: H Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry