iris

1 of 3

noun (1)

ˈī-rəs 

plural irises also irides ˈī-rə-ˌdēz 

ˈir-ə-

1

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

2

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

3

: rainbow

Illustration of iris

• iris 2

iris

2 of 3

verb

irised; irising; irises

transitive verb

: to make iridescent

Iris

3 of 3

noun (2)

ˈī-rəs 

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

Examples of iris in a Sentence

Recent Examples on the Web

Noun

These stray images were then blasted away by a blazing sun that completely filled the space of awareness before transforming itself into a gigantic eyeball—a sighted sun with a black circle of iris. —Michael Pollan, The Atlantic, 26 Jan. 2026

The ambrette and iris in You create this soft, skin-like foundation that grounds all that rhubarb brightness. —Kimberly Wilson, Essence, 22 Jan. 2026

Iconic photographs from pioneering observatories of decades past, such as the Hubble Space Telescope and the Spitzer Space Telescope, had shown this maelstrom as an extended haze around the nebula’s glowing iris. —Joseph Howlett, Scientific American, 20 Jan. 2026

Sitting on his living room couch this week, Rodriguez said doctors told him the projectile that hit him in his eye damaged his iris, cornea and lens. —Ruben Vives, Los Angeles Times, 16 Jan. 2026

Word History

Etymology

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

Verb

1816, in the meaning defined above

Noun (2)

15th century, in the meaning defined above

Phrases Containing iris

• bearded iris
• blue flag iris
• iris diaphragm
• Japanese iris

Rhymes for iris

• gyrus
• pyrus
• virus
• adenovirus
• baculovirus
• coronavirus
• enterovirus
• poliovirus
• antivirus
• herpesvirus
• parvovirus
• reovirus

Kids Definition

iris

noun

ˈī-rəs

plural irises

-rə-səz

or irides

ˈī-rə-ˌdēz, 

ˈir-ə-

1

: the colored part around the pupil of the eye that changes in size to control the amount of light entering the pupil

2

also plural iris : any of a large genus of plants with long pointed leaves and large usually brightly colored flowers

3

: iris diaphragm

Medical Definition

iris

noun

ˈī-rəs 

plural irises or irides 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