There are 2 main definitions of iris in English:


Syllabification: i·ris
Pronunciation: /ˈīris


1A flat, colored, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the center.
More example sentences
  • The thin sheet of circular muscle of the iris which constricts the pupil of the eye is also known as a sphincter.
  • The walking wounded were often blind, their pupils, irises, and corneas burned out.
  • The colored circular membrane in the eye just behind the cornea is called the iris.
1.1 (also iris diaphragm) An adjustable diaphragm of thin overlapping plates for regulating the size of a central hole, especially for the admission of light to a lens.
More example sentences
  • The incorporation of a variable iris diaphragm into the optical couplers allows the power of the beams to be independently set.
  • In experiments to find the effect of lens diameter he invented the familiar iris diaphragm.
  • This is the job of the iris diaphragm, a series of overlapping metal plates that can fold in on each other or expand out.
2A plant with sword-shaped leaves and showy flowers, typically purple, yellow, or white. Native to both Eurasia and North America, it is widely cultivated as an ornamental.
More example sentences
  • The newspaperman had a love for a myriad of different flower species and soon divided his interests between roses, irises, lilacs and native California plants.
  • It spreads by underground fleshy stems called rhizomes; rhizomes are found on many plants, from irises to agapanthus, from ferns to Bermuda grass.
  • Daffodils, iris, tulips, gladiolus, hyacinth, and daylilies are just some of the many bulb favorites.
3A rainbow or a rainbowlike appearance.


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(Of an aperture, typically that of a lens) open or close in the manner of an iris or iris diaphragm.
More example sentences
  • Ann tugged at his arm and pointed down to the hull's underbelly: a round opening had irised out in it, brightly lit from inside.
  • A swirling vortex of yellow and white light irised open from a small dot to a man-sized portal just above the deck in front of Illeen.
  • As the last scene irised out to the familiar credits I was actually happy to have it all over.


modern Latin, via Latin from Greek iris 'rainbow, iris'.

Definition of iris in:

There are 2 main definitions of iris in English:


Syllabification: I·ris
Pronunciation: /ˈīris
Greek Mythology
The goddess of the rainbow, who acted as a messenger of the gods.

Definition of iris in: