aside of . aside of {prep.}, {dialect} Beside; by the side of. Mary sits aside of her sister on the bus. Categories: add yours {dialect} {prep.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: A Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Discuss