/ Dictionary / Index H horse chestnut: Meaning and Definition of Find definitions for: horse' chest"nut Pronunciation: [key] a tree, Aesculus hippocastanum, native to the Old World, having digitate leaves and upright clusters of white flowers. the shiny, brown, nutlike seed of this tree or of other trees of the genus Aesculus. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. horsecar horse clam 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