flat as a pancake . flat as a pancake {adj. phr.} Very level; very flat; having no mountains or hills. A great part of the American Midwest is as flat as a pancake. Categories: add yours {adj. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: F Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry