/ Dictionary / Index P periodontitis: Meaning and Definition of Find definitions for: per•i•o•don•ti•tis Pronunciation: (per"ē-ō-don-tī'tis), [key] — n. Dentistry. inflammation of the periodontium caused by bacteria that infect the roots of teeth and the surrounding gum crevices, producing bleeding, pus formation, and gradual loss of bone and the tissues that support the teeth. Cf.(def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: periodontitis (Thesaurus) periodontist periodontium Related Content Daily Word Quiz: hale Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language