/ Dictionary / Index P pleomorphism: Meaning and Definition of Find definitions for: ple•o•mor•phism Pronunciation: (plē"u-môr'fiz-um), [key] — n. Biol. existence of an organism in two or more distinct forms during the life cycle; polymorphism. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pleomorphism (Thesaurus) pleomorphic pleon Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language