/ Dictionary / Index R root pressure: Meaning and Definition of Find definitions for: root' pres"sure Pronunciation: [key] — Bot. Bot. osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. root position root rot Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language