/ Dictionary / Index P provirus: Meaning and Definition of Find definitions for: pro•vi•rus Pronunciation: (prō'vī"rus, prō-vī'-), [key] — pl. -rus•es. a viral form that is incorporated into the genetic material of a host cell. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: provirus (Thesaurus) proving ground provision Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language