in and out . in and out {adv. phr.} 1. Coming in and going out often. He was very busy Saturday and was in and out all day. 2. See: INSIDE OUT (2). Categories: add yours {adv. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: I Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Discuss