iris

noun \ ˈī-rəs \

Updated on: 16 Apr 2018

Definition of iris

plural irises also irides play \ˈī-rə-ˌdēz, ˈir-ə-\

1 : rainbow

a : the opaque contractile diaphragm perforated by the pupil and forming the colored portion of the eye — see eye illustration

b : iris diaphragm; also : a similar device with a circular opening that can be varied in size

3 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

See iris defined for English-language learners

See iris defined for kids

Recent Examples of iris from the Web

Some of the beauty that caught my eye ranged from wild turkeys allowing me to get closer than usual to wild iris piercing through thick layers of leaves to display their vibrant beauty.

— joe songer, AL.com, "Spring is in full swing in Alabama," 10 Apr. 2018
Fat deposits may also be seen in the eye, as a grey ring around the outside of the iris, the coloured part of the eye.

— adam taylor, CNN, "Heart disease risk may show in your earlobes, eyes, fingers," 29 Mar. 2018
About 45% of people over the age of 40 have this fatty halo around their iris, rising to about 70% of people over the age of 60.

— adam taylor, CNN, "Heart disease risk may show in your earlobes, eyes, fingers," 29 Mar. 2018
The almond blossoms, gnarled trees and irises that dotted the French landscape reminded him of nature scenes painted in Kyoto.

— nina siegal, New York Times, "Van Gogh Never Visited Japan, but He Saw It Everywhere," 26 Mar. 2018
The Iris Society presents tall bearded, small bearded and aril-bred irises in the Los Angeles County Arboretum's Ayres Hall.

— jeanette marantos, latimes.com, "It's spring gardening season: 12 plant sales to get you digging," 22 Mar. 2018
Do not divide those in active growth, such as Louisiana irises and calla lilies.

— dan gill, NOLA.com, "This week's gardening tips: plant lettuce and clean out aquatic garden," 24 Feb. 2018
The lens of your eye lies behind the iris and the pupil.

— alice adams, Houston Chronicle, "Eye-witness report: What you should know about cataracts," 15 Mar. 2018
Is there a way to get rid of the grass or kill the grass without killing my iris and daylilies?

— melinda myers, Milwaukee Journal Sentinel, "Tall grasses, upright shrubs provide screening," 9 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'iris.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of iris

Origin and Etymology of iris

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 ¹wire). 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.

NEW! Time Traveler

First Known Use: 15th century

in the meaning defined at sense 1

See Words from the same year

Other Seed Plant Terms

aubergine, box, bramble, briar, composite, perpetual, pulse, trefoil

iris

verb

Definition of iris

transitive verb

: to make iridescent

First Known Use of iris

1816

in the meaning defined above

See Words from the same year

NEW! Time Traveler

Iris

noun \ ˈī-rəs \

Definition of Iris

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

Origin and Etymology of iris

Latin, from Greek

NEW! Time Traveler

First Known Use: 15th century

in the meaning defined above

See Words from the same year

Other Mythology and Folklore Terms

elysian, fay, muse, nimbus, phoenix

IRIS Defined for English Language Learners

iris

noun

Definition of iris for English Language Learners

: the colored part of your eye
: a plant with long pointed leaves and large blue or yellow flowers

IRIS Defined for Kids

iris

noun \ ˈī-rəs \

Definition of iris for Students

1 : the colored part around the pupil of an eye

2 : a plant with long pointed leaves and large usually brightly colored flowers

Medical Dictionary

iris

noun \ ˈī-rəs \

medical Definition of iris

plural irises or irides play \ˈī-rə-ˌdēz, ˈir-ə-\

1 : 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

2 : iris diaphragm