/ Dictionary / Index A acorn worm: Meaning and Definition of Find definitions for: a'corn worm" Pronunciation: [key] any of several burrowing, often brilliantly colored hemichordates of the class Enteropneusta, usually found in intertidal sand and mud, having an acorn-shaped proboscis and collar. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. acorn tube acotyledon Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language