Dictionary.com
Thesaurus.com

procto

1 American  
[prok-toh] / ˈprɒk toʊ /

noun

Informal.

PLURAL

proctos
  1. proctosigmoidoscopy.


procto- 2 American  
especially before a vowel, proct-.
  1. a combining form meaning “anus,” “rectum,” used in the formation of compound words.

    proctoscope.


procto- British  

combining form

  1. indicating the anus or rectum

    proctology

"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

Usage

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.

Etymology

Origin of procto1

By shortening

Origin of procto-1

< Greek prōkto-, combining form of prōktós