/ Dictionary / Index P posse comitatus: Meaning and Definition of Find definitions for: pos•se co•mi•ta•tus Pronunciation: (pos'ē kom"i-tä'tus, -tā'-), [key] the body of persons that a peace officer of a county is empowered to call upon for assistance in preserving the peace, making arrests, and serving writs. a body of persons so called into service. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. posse possess Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language