/ Dictionary / Index S stem rust: Meaning and Definition of Find definitions for: stem' rust" Pronunciation: [key] — Plant Pathol. Plant Pathol. any of several fungal diseases of plants affecting the stems, esp. a disease of wheat and other grasses characterized by pustules of red and then black spores. any of the fungi causing such a disease. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. stem rot stemson Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language