/ Dictionary / Index C copper spot: Meaning and Definition of Find definitions for: cop'per spot' Pronunciation: [key] — Plant Pathol. Plant Pathol. a disease of grasses characterized by coppery or orange spore masses covering the blades, caused by a fungus, Gloeocercospora sorghi. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coppersmith copper sulfate Related Content Daily Word Quiz: laudable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language