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a combining form of Latin origin used, with the meanings “rainbow,” “iridescent,” “iris (of the eye),” “Iris (the genus),” and “iridium,” in the formation of compound words: iridopupillary; iridosmine; iridotomy.
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Also especially before a vowel, irid-.

Origin of irido-

Combining form representing New Latin, Latin, Greek īrid- (stem of îris) rainbow, iris, etc.; see iris
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does irido- mean?

Irido- is a combining form used like a prefix with several meanings:

  • In medicine, irido- can refer to the iris, the colored portion of the eye.
  • In botany, it can refer to the genus Iris, a family of beautiful flowering plants.
  • In chemistry, irido- represents the precious metallic element iridium.

Irido- can also denote “rainbow” and “iridescent.” In fact, irido- comes from the Greek îris, meaning “rainbow” and “iris.”

As you likely guessed, the Greek îris is the source of the English word iris and the shimmering word iridescent. In Greek mythology, Iris was the goddess of the rainbow and acted as a messenger to the gods.

What are variants of irido-?

When combined with words or word elements that begin with a vowel, irido- becomes irid-, as in iridectomy.

Examples of irido-

One example of a term from medicine that features the combining form irido- is iridotomy, “incision of the iris.”

We know that irido- means “iris,” here indicating the colored portion of the eye, in medical terms. The -tomy part of the word is a combining form that refers to the “cutting” or “incision” of an organ. Iridotomy literally translates to “cutting into the iris of the eye.” Eek!

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

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

Break it down!

The combining form -pathy is used to mean “disease.” What part of the body does iridopathy affect?

British Dictionary definitions for irido-


before a vowel irid-

combining form
denoting the iris of the eye or the genus of plantsiridaceous
denoting a rainbowiridescent

Word Origin for irido-

from Latin irid-, iris
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