Anatomy. the contractile, circular diaphragm forming the colored portion of the eye and containing a circular opening, the pupil, in its center.
Botany. any plant of the genus Iris, having showy flowers and sword-shaped leaves.
a flower of this plant.
(initial capital letter) a messenger of the gods, regarded as the goddess of the rainbow.
a rainbow.
any appearance resembling a rainbow.
Movies, Television. an iris-in or iris-out.
Optics, Photography. iris diaphragm.
the coloured muscular diaphragm that surrounds and controls the size of the pupil
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
Also called: rainbow quartz. a form of quartz that reflects light polychromatically from internal fractures
a rare or poetic word for rainbow
something resembling a rainbow; iridescence
short for iris diaphragm
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”
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."
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World uses the iris for ID confirmation because it is the most unique part of a person, even more so than a fingerprint.
From BBC • Apr. 17, 2026
While palm, face or iris payment and authentication aren’t widespread in the U.S., more commercial trials are popping up, and this type of biometric technology has the potential to proliferate over the next few years.
From The Wall Street Journal • Mar. 20, 2026
The gadget relies on iridology, a technique by which iris colors and markings are believed to reveal information about a person's health, but which is generally considered scientifically unreliable.
From Barron's • Jan. 12, 2026
To receive a verified World ID, people can choose to send their iris image to their phone and that data are encrypted, meaning that the company can’t view or access the information.
From Los Angeles Times • May 12, 2025
His are brown, like mine, like most Indians’, but so dark that the pupil almost completely fades into the iris.
From "Love, Hate & Other Filters" by Samira Ahmed
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
