/ Dictionary / Index P psyllid yellows: Meaning and Definition of Find definitions for: psyl'lid yel'lows Pronunciation: [key] — (used with a sing. or pl. v.) Plant Pathol. (used with a sing. or pl. v.)Plant Pathol. a viral disease transmitted by the potato psyllid, causing the young leaves of potatoes, tomatoes, eggplants, and peppers to curl and turn yellow or purplish. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. psylla psyllium Related Content Daily Word Quiz: apogee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language