/ Dictionary / Index H horned oak gall: Meaning and Definition of Find definitions for: horned' oak' gall" Pronunciation: [key] a small, round tumor, formed around wasp eggs laid in the branches of a pin oak tree, that disrupts the flow of nutrients to the tree, with consequent defoliation and death. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. horned lizard horned poppy Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language