/ Dictionary / Index E expansion card: Meaning and Definition of Find definitions for: expan'sion card" Pronunciation: [key] — Computers. Computers. a card in a computer on which additional chips can be mounted to expand the computer's capabilities. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. expansion bolt expansion chamber Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language