tight-lipped tight-lipped {adj.} A taciturn person; one who doesn't say much. The witness was tight-lipped about what she saw for fear of physical retaliation by the mob. Categories: add yours {adj.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: T Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Leave my opinion