/ Dictionary / Index O orange rust: Meaning and Definition of Find definitions for: or'ange rust' Pronunciation: [key] — Plant Pathol. Plant Pathol. a disease of blackberries and raspberries, characterized by an orange, powdery mass of spores on the undersides of the leaves and stunted, misshapen foliage, caused by a rust fungus, Gymnoconia interstitialis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. orange pekoe orangery Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language