brain bucket . brain bucket {n.}, {slang} A motorcycle helmet. If you want to share a ride with me, you've got to wear a brain bucket. Categories: add yours {n.} {slang} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: B Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Post my comment