/ Dictionary / Index P phytophthora: Meaning and Definition of Find definitions for: phy•toph•tho•ra Pronunciation: (fī-tof'thur-u), [key] — n. any of a group of fungi of the genus Phytophthora, which cause a serious plant disease, esp. affecting apple and pear trees and potatoes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phytophthora (Thesaurus) phytophagous phytoplankton Related Content Daily Word Quiz: jovial Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language