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• iris
  iris

  noun

  the contractile, circular diaphragm forming the colored portion of the eye and containing a circular opening, the pupil, in its center.
• Iris
  Iris

  noun

  a female given name.

iris

¹ American  

[ahy-ris] / ˈaɪ rɪs /

noun

irises, plural irides plural

1. Anatomy. the contractile, circular diaphragm forming the colored portion of the eye and containing a circular opening, the pupil, in its center.

2. Botany. any plant of the genus Iris, having showy flowers and sword-shaped leaves.

3. a flower of this plant.

4. (initial capital letter) a messenger of the gods, regarded as the goddess of the rainbow.

5. a rainbow.

6. any appearance resembling a rainbow.

7. Movies, Television. an iris-in or iris-out.

8. Optics, Photography. iris diaphragm.

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verb (used without object)

1. Movies. to begin or end a take or scene with an iris-in or iris-out, achieved by manipulation of an iris diaphragm on the camera or by editing the film.

Iris ² American  

[ahy-ris] / ˈaɪ rɪs /

noun

1. a female given name.

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iris ¹ British  

/ ˈaɪrɪs /

noun

1. the coloured muscular diaphragm that surrounds and controls the size of the pupil

2. Also called: fleur-de-lys.  any plant of the iridaceous genus Iris, having brightly coloured flowers composed of three petals and three drooping sepals See also flag 3 orris 1 stinking iris

3. Also called: rainbow quartz.  a form of quartz that reflects light polychromatically from internal fractures

4. a rare or poetic word for rainbow

5. something resembling a rainbow; iridescence

6. short for iris diaphragm

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Iris ² British  

/ ˈaɪrɪs /

noun

1. the goddess of the rainbow along which she travelled to earth as a messenger of the gods

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iris Scientific  

/ ī′rĭs /

irises plural

1. The colored, muscular ring around the pupil of the eye in vertebrate animals, located between the cornea and lens. Contraction and expansion of the iris controls the size of the pupil, thereby regulating the amount of light reaching the retina.

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iris Cultural  

1. The colored membrane of the eye, surrounding the pupil, which by contracting and expanding regulates the amount of light that enters the eye.

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Etymology

Origin of iris

First recorded in 1350–1400; Middle English, from Latin Īris, īris, from Greek Îris, îris “rainbow, goddess of the rainbow, halo, iris flower or root, iridescent crystal”; in some senses, from New Latin, from Greek: “diaphragm of eye”

Explanation

Your iris is the colored part of your eye that surrounds the black pupil in the center. If your irises are brown, you can say you have brown eyes. The job of the iris is to determine how large or small the pupil is, depending on the amount of light available. Your iris protects your eye's retina, by controlling how much light reaches it, and helps you to see. Another kind of iris is a bright flower with long, spiky leaves. Both irises take their names from the Greek iris, "rainbow."

Example Sentences

IriHealth is preparing to launch, for only about $50, a small smartphone extension that would scan a user's iris.

From Barron's • Jan. 12, 2026

And the Sam Altman-backed World project aims to scan every iris on Earth for its anonymous identification platform—if privacy concerns don’t get in the way.

From The Wall Street Journal • Dec. 27, 2025

Other procedures like laser depigmentation and iris implants have also been used to change the eye color, but may result in corneal damage or vision loss as well.

From Salon • May 4, 2025

Grayson is blind, the result of a rare genetic disorder that stunts the development of the iris and the crystalline lens covering the eye.

From Los Angeles Times • Jan. 28, 2025

“I planted the iris seed,” she said, gesturing to the empty spot where the old iris once lived.

From "The Science of Breakable Things" by Tae Keller