be set on . be set on or upon {v. phr.} To be determined about something. Tow is set upon leaving his Chicago job for Tokyo, Japan, although he speaks only English. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: B Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry