split second . split second {n.} A very short time; less than a second. The lightning flash lasted a split second, and then disappeared. Categories: add yours time {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