under the weather . under the weather {adv. phr.} In bad health or low spirits. Mary called in today asking for a sick day as she is under the weather. Categories: add yours {adv. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: U Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Read comments Comment on this entry