/ Dictionary / Index P period of rotation: Meaning and Definition of Find definitions for: pe'riod of rota'tion Pronunciation: [key] — Astron. Astron. period (def. 19a). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. period of revolution periodontal 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