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a combining form meaning “cutting, incision” of an organ, “excision” of an object, as specified by the initial element (appendectomy; lithotomy); also occurring in abstract nouns corresponding to adjectives ending in -tomous (dichotomy).
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Compare -tome, tomo-, -tomous.

Origin of -tomy

Representing Greek -tomia; see -tome, -y3
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does -tomy mean?

The combining form -tomy used like a suffix has several meanings. In medical terms, it refers to “cutting,” usually in reference to the surgical incision into an organ but sometimes as part of the removal of an object from the body.

The combining form -tomy is also occasionally used to form abstract nouns in reference to some type of “division,” as in dichotomy, “division into two parts.”

The combining form -tomy comes from the Greek -tomia, meaning “cutting,” which is based on the verb témnein, “to cut.”

Related to -tomy are the combining forms -tome, -tomous, and tomo-. Also related to -tomy is -ectomy, which literally means “cutting out of” and specifically refers to the excision or removal of organs, as in a tonsillectomy.

Learn more about -ectomy in our Words That Use article for the form.

Also related to tómos is atom. What’s the big idea behind atoms and cutting? Find out in our Origin section for this term.

Examples of -tomy

An example of a word you may have encountered that features -tomy is craniotomy, “the operation of opening the skull, usually for operations on the brain.”

The combining form cranio- may also look familiar: it represents the cranium, also known as “skull.” The form -tomy means “incision,” as we’ve seen. So, craniotomy literally translates to “skull incision.”

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

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

Break it down!

The combining form entero- means “intestine,” a major organ in the digestive system. What does the surgical procedure of an enterotomy involve?

How to use -tomy in a sentence

British Dictionary definitions for -tomy


n combining form
indicating a surgical cutting of a specified part or tissuelobotomy

Word Origin for -tomy

from Greek -tomia; see -tome
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