wheelhorse wheelhorse {n. phr.} A reliable and industrious worker on whom one may depend. Jake is such a good worker that he is the wheelhorse of our tiny firm. Categories: add yours {n. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: W Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Leave my opinion