/ Dictionary / Index A acorn barnacle: Meaning and Definition of Find definitions for: a'corn bar"nacle. Pronunciation: [key] See under (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. acorn acorn chair Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language