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Definition of algo-

a combining form meaning “pain,” used in the formation of compound words: algophobia.
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Origin of algo-

Combining form representing Greek álgos
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does algo- mean?

Algo- is a combining form used like a prefix meaning “pain.” It is occasionally used in medical terms, especially in psychiatry and pathology.

Algo- comes from the Greek álgos, meaning “pain.” Similar in meaning and use to algo- are odyno- and -odynia, which derive from odýnē, also meaning “pain.”

Corresponding forms of algo- combined to the end of words are -algia, as in ovarialgia, or -algy, as in coxalgy. Learn more about these forms in our Words That Use articles for each.

Examples of algo-

One example of a term that features the combining form algo- is algophobia, “an irrational or disproportionate fear of pain.”

Algo- means “pain,” as we have seen. The -phobia part of the word may also look familiar. It means “fear.” Algophobia literally translates to “fear of pain.”

What are some words that use or are related to the combining form algo-?

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

Many words that begin with the exact letters algo- or alg- are not using the combining form algo- to denote “pain.” Algorithm, algology, and algae are three examples. Learn more about the history and meaning of these words at our entries for them.

Break it down!

The combining form -meter means “measure.” It is used to name instruments that measure various quantities or qualities. What does an algometer measure?

How to use algo- in a sentence

British Dictionary definitions for algo-


combining form
denoting painalgometer; algophobia

Word Origin for algo-

from Greek algos pain
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 algo-


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