knock down knock down {v. phr.} To reduce; lower. The realtors said that if we decided to buy the house, they would knock the price down by 10%. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: K Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Post my comment