[ prok-toh ]
/ ˈprɒk toʊ /
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noun, plural proc·tos.Informal.
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Origin of procto

By shortening

Other definitions for procto (2 of 2)


a combining form meaning “anus,” “rectum,” used in the formation of compound words: proctoscope.
Also especially before a vowel, proct-.

Origin of procto-

<Greek prōkto-, combining form of prōktós
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does procto- mean?

Procto- is a combining form used like a prefix meaning “anus” or “rectum,” technical terms for parts of the butt. It is used in some medical terms, especially in pathology and surgery.

Procto- comes from the Greek prōktós, meaning “anus.”

What are variants of procto-?

When combined with words or word elements that begin with a vowel, procto- becomes proct-, as in proctalgia.

Examples of procto-

An example of a word you may have encountered that features procto- is proctology, “the branch of medicine dealing with the rectum and anus.” A specialist in this is a proctologist.

The procto- portion of the word refers to anus and the rectum. The -logy portion of the word is used to name sciences, studies, or bodies of knowledge. Proctology literally means “study of the rectum and anus.”

What are some words that use the combining form procto- or proct-?

What are some other forms that procto- may be commonly confused with?

Not every word that begins with the exact letters procto- or proct- is necessarily using the combining forming procto- to denote “anus.” Proctor is one example. Learn the very different history and meaning of proctor at our entry for the word.

Break it down!

The combining form -tomy means “cutting” or “incision” of an organ. What does the medical procedure of a proctotomy involve?

British Dictionary definitions for procto


before a vowel proct-

combining form
indicating the anus or rectumproctology

Word Origin for procto-

from Greek prōktos
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for procto


Anus or rectum:proctalgia.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.