/ Dictionary / Index U union card: Meaning and Definition of Find definitions for: un'ion card" Pronunciation: [key] a card identifying one as a member of a particular labor union. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. union buster union catalog Related Content Daily Word Quiz: cur Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language