/ Dictionary / Index H horse conch: Meaning and Definition of Find definitions for: horse' conch" Pronunciation: [key] a marine gastropod, Pleuroploca gigantea, having a yellowish, spired shell that grows to a length of 2 ft. (0.6 m). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. horse-collar horse-coper Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language