- 1A flat, coloured, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the centre.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 showy flowers, typically of purple or yellow, and sword-shaped leaves. Irises are native to both Eurasia and North America and widely cultivated as ornamentals.
More example sentences
- Genus Iris, family Iridaceae (the iris family): many species and numerous hybrids. The iris family also includes the gladioli, crocuses, and freesias
- 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.
verb[no object, with adverbial of direction] Back to top
- (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'.
More definitions of IrisDefinition of iris in:
- The US English dictionary