mail order . mail order {n. phr.} A purchase made by mail. If you don't have a chance to go to a store, you can sometimes make a purchase by mail order. Categories: add yours {n. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: M Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Discuss