drop a line drop a line {v. phr.} To write someone a short letter or note. Please drop me a line when you get to Paris; I'd like to know that you've arrived safely. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: D Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Add my comment