senior citizen . senior citizen {n.} An older person, often one who has retired from active work or employment. Mrs. North, the history teacher, is a senior citizen. Categories: add yours {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: S Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Add my comment