second cousin . second cousin {n.} A child of your father's or mother's first cousin. Mary and Jane are second cousins. Categories: add yours children {n.} 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 Post my comment