/ Dictionary / Index P parasitism: Meaning and Definition of Find definitions for: par•a•sit•ism Pronunciation: (par'u-sī-tiz"um, -si-), [key] — n. a relation between organisms in which one lives as a parasite on another. a parasitic mode of life or existence. a diseased condition due to parasites. (in some totalitarian countries) unemployment or refusal to work. employment in work considered nonessential by the state. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: parasitism (Thesaurus) parasiticide parasitize Related Content Daily Word Quiz: miscreant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language