/ Dictionary / Index P picloram: Meaning and Definition of Find definitions for: pic•lo•ram Pronunciation: (pik'lu-ram", pī'klu-), [key] — n. Chem. a colorless powder, CHClNO, used as a systemic herbicide for controlling annual weeds and deep-rooted perennials on noncrop land. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. picky picnic Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language