/ Dictionary / Index P periodontal: Meaning and Definition of Find definitions for: per•i•o•don•tal Pronunciation: (per"ē-u-don'tl), [key] — adj. Dentistry. of or pertaining to the periodontium. of or pertaining to periodontics. of or pertaining to the periodontal membrane. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: periodontal (Thesaurus) period of rotation periodontal disease Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language