think up think up {v.} To invent or discover by thinking; have a new idea of. Mary thought up a funny game for the children to play. Categories: add yours children {v.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: T Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Discuss