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a combining form representing colon2 in compound words: colostomy.
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Also especially before a vowel, col-.

Other definitions for colo- (2 of 2)


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does colo- mean?

Colo- is a combining form used like a prefix representing the word colon, the part of the large intestine extending from the cecum to the rectum. It is often used in medical terms.

Colo- comes from the Greek kólon, meaning “large intestine.” The Greek kólon is also the source of such words as colic and colicky, a word which many parents may know all too well.

What are variants of colo-?

When combined with words or word elements that begin with a vowel, colo- becomes col-, as in colitis.

Examples of colo-

An example of a word you may have encountered that features colo- is coloptosis, also known as a prolapse (falling down) of the colon.

We know colo- represents “colon.” What about -ptosis? The -ptosis part of the word refers to “a falling,” from the Greek ptṓsis. Coloptosis literally translates to “colon falling.”

Another common word that features colo- is colorectal, as in colorectal cancer. The rectal part of the word refers to the rectum. And a coloscopy is another word for a colonoscopy, an important (if very, um, personal) visual inspection of the interior of the colon with a flexible, lighted tube inserted through the rectum.

What are some words that use the combining form colo-?

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

Not every word that begins with the exact letters colo- or col- is necessarily using the combining form colo- to represent “colon.” For starters, the word colony and related terms come from Latin for “farmer.”

As if that wasn’t confusing enough, col- is commonly used as a variant of the prefix com- (“with, together”) before the letter –l-, as in collaborate.

Break it down!

The combining form -tomy means “cutting” or “incision.” With this in mind, what kind of surgical procedure is a colotomy?

How to use colo- in a sentence

British Dictionary definitions for colo- (1 of 2)


before a vowel col-

combining form
indicating the coloncolostomy; colotomy

British Dictionary definitions for colo- (2 of 2)


abbreviation for
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 colo-


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