n.
A word that one uses to provoke a fight or hostility. Often used in the plural: "Fighting words are categorically excluded from the protection of the First Amendment ... [because] their content embodies a particularly intolerable and socially unnecessary mode of expressing whatever idea the speaker wishes to convey" (Antonin Scalia).
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.