/ Dictionary / Index T trail boss: Meaning and Definition of Find definitions for: trail' boss" Pronunciation: [key] (in Western U.S.) a person responsible for driving a herd of cattle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trailboard trailer Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language