suit up suit up {v. phr.} To don a uniform or sports outfit. The veterans like to suit up for the Fourth of July parade. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: S Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry