1 of 3

noun (1)

plural irises also irides ˈī-rə-ˌdēz How to pronounce iris (audio)
: the opaque contractile diaphragm perforated by the pupil and forming the colored portion of the eye see eye illustration
: iris diaphragm
also : a similar device with a circular opening that can be varied in size
also plural iris : any of a large genus (Iris of the family Iridaceae, the iris family) of perennial herbaceous plants with linear usually basal leaves and large showy flowers

Illustration of iris

Illustration of iris
  • iris 2


2 of 3


irised; irising; irises

transitive verb

: to make iridescent


3 of 3

noun (2)

: the Greek goddess of the rainbow and a messenger of the gods

Examples of iris in a Sentence

Recent Examples on the Web
Stefani dressed on theme, rocking a glittery, purple bodysuit with an enlarged iris attached to the front of the look, as the pair sang in harmony. Angel Saunders, Peoplemag, 17 May 2024 Caesar can digitally freeze everything around him one second, then stare lovingly at Julia via a silent-cinema iris shot the next. David Fear, Rolling Stone, 16 May 2024 See all Example Sentences for iris 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'iris.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Noun (1)

Middle English, "iris of the eye, the plant Iris germanica," borrowed from Latin īrid-, īris "rainbow, the plant Iris pallida or related species," borrowed from Greek īrid-, îris "rainbow, iridescent halo around the moon, a flame, etc., iris of the eye, the plant Iris pallida or related species," going back to *wīrid-, *wīris, of uncertain origin

Note: Traditionally, Greek îris "rainbow" (for which an original digamma [letter representing the sound w] is assured by an inscription from Corinth and the metrics of epic poetry) has been regarded as a derivative of Indo-European *u̯ei̯H- "plait, wrap," parallel to Germanic *wīr- (see wire entry 1). However, the variant éris recorded by the Greek lexicographer Hesychius, as well as the dubious character of *wīrid- as an Indo-European formation (< *u̯ih1-r-i-?) has drawn this etymology into question. Perhaps a substratal word.

Noun (2)

Latin, from Greek

First Known Use

Noun (1)

15th century, in the meaning defined at sense 3


1816, in the meaning defined above

Noun (2)

15th century, in the meaning defined above

Time Traveler
The first known use of iris was in the 15th century

Dictionary Entries Near iris

Cite this Entry

“Iris.” Dictionary, Merriam-Webster, Accessed 29 May. 2024.

Kids Definition


plural irises
or irides
: the colored part around the pupil of the eye that changes in size to control the amount of light entering the pupil
also plural iris : any of a large genus of plants with long pointed leaves and large usually brightly colored flowers

Medical Definition


plural irises or irides ˈī-rə-ˌdēz How to pronounce iris (audio) ˈir-ə- How to pronounce iris (audio)
: the opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye, is perforated by the pupil and is continuous peripherally with the ciliary body, has a deeply pigmented posterior surface which excludes the entrance of light except through the pupil and a colored anterior surface which determines the color of the eyes

More from Merriam-Webster on iris

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!