/ Dictionary / Index P procto: Meaning and Definition of Find definitions for: proc•to Pronunciation: (prok'tō), [key] — pl. -tos. proctosigmoidoscopy. procto- Pronunciation: [key] a combining form meaning “anus,” “rectum,” used in the formation of compound words: proctoscope. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. proctitis proctoclysis Related Content Daily Word Quiz: pristine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language