copper spot: Meaning and Definition of

cop'per spot'

Pronunciation: [key]
— Plant Pathol. Plant Pathol.
  1. 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.