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iris

i·ris / ˈīris/ • n. 1. a flat, colored, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the center. ∎  (also iris diaphragm) an adjustable diaphragm of thin overlapping plates for regulating the size of a central hole, esp. for the admission of light to a lens. 2. a 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. • Genus Iris, family Iridaceae (the iris family): many species and numerous hybrids, including the crested dwarf iris (I. cristata) and the sweet iris (I. pallida). The iris family also includes the gladioli, crocuses, and freesias. 3. a rainbow or a rainbowlike appearance. • v. [intr.] (of an aperture, typically that of a lens) open or close in the manner of an iris or iris diaphragm.

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"iris." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-3

"iris." The Oxford Pocket Dictionary of Current English. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-3

iris

iris The pigmented ring of muscular tissue, lying between the cornea and the lens, in the eyes of vertebrates and some cephalopod molluscs. It has a central hole (the pupil) through which light enters the eye and it contains both circular and radial muscles. Reflex contraction of the former occurs in bright light to reduce the diameter of the pupil (see pupillary reflex); contraction of the radial muscles in dim light increases the pupil diameter and therefore the amount of light entering the eye. Colour is determined by the amount of the pigment melanin in the iris. Blue eyes result from relatively little melanin; grey and brown eyes from increasingly larger amounts.

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"iris." A Dictionary of Biology. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." A Dictionary of Biology. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/iris-0

"iris." A Dictionary of Biology. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/iris-0

iris

iris (I-ris) n. the part of the eye that regulates the amount of light that enters. It forms a coloured muscular diaphragm across the front of the lens; light enters through a central opening (the pupil). Contraction of different sets of muscles of the iris causes the pupil to dilate in dim light and to contract in bright light. i. bombé an abnormal condition of the eye in which the iris bulges forward towards the cornea.

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"iris." A Dictionary of Nursing. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." A Dictionary of Nursing. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/iris

"iris." A Dictionary of Nursing. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/iris

iris

iris species of crystal XIV; rainbow XV; flat circular coloured membrane in the aqueous humour of the eye; genus of tuberous or bulbous plants XVI. — L. īris — Gr. īris rainbow, coloured circle, etc., iris (plant), (I-) female messenger of the gods, whose sign was a rainbow.

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"iris." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-4

"iris." The Concise Oxford Dictionary of English Etymology. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-4

iris

iris Coloured part of the eye. It controls the amount of light that enters the pupil in the centre of the eye by increasing or decreasing the size of the pupil. These changes are brought about by muscles in the iris contracting or relaxing.

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"iris." World Encyclopedia. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." World Encyclopedia. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/iris-0

"iris." World Encyclopedia. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/iris-0

Iris

Iris. Opera in 3 acts by Mascagni, to lib. by Illica. Prod. Rome 1898; rev. version Milan 1899, Philadelphia 1902, London 1919, Wexford 1995.

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"Iris." The Concise Oxford Dictionary of Music. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"Iris." The Concise Oxford Dictionary of Music. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/iris

"Iris." The Concise Oxford Dictionary of Music. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/arts/dictionaries-thesauruses-pictures-and-press-releases/iris

Iris (river, Turkey)

Iris, river: see Yeşil Irmak.

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"Iris (river, Turkey)." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

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"Iris (river, Turkey)." The Columbia Encyclopedia, 6th ed.. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/iris-river-turkey

iris (in anatomy)

iris: see eye.

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"iris (in anatomy)." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

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Iris

Iris (ˈaɪrɪs) infrared intruder system

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"Iris." The Oxford Dictionary of Abbreviations. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

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"Iris." The Oxford Dictionary of Abbreviations. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-0

iris

irisarris, Clarice, Harries, Harris, Paris •mattress • actress • benefactress •Polaris • enchantress •derris, Nerys, terrace •Emrys • empress •directress, Electress •temptress • sempstress •Apollinaris, heiress •waitress • seamstress • ex libris •headmistress, mistress •housemistress • toastmistress •schoolmistress • ancestress •dentifrice •iris, Osiristigress, Tigris •cypress •Boris, doch-an-dorris, Doris, Horace, Maurice, Norris, orris •cantoris, Dolores, loris •laundress • fortress • jointress •hubris • buttress •conductress, instructress, seductress •huntress • peeress • Beatrice •arbitress • berberis • anchoress •ephemeris • ambassadress •adventuress • clitoris • authoress •avarice

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"iris." Oxford Dictionary of Rhymes. . Encyclopedia.com. 24 Aug. 2017 <http://www.encyclopedia.com>.

"iris." Oxford Dictionary of Rhymes. . Encyclopedia.com. (August 24, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-1

"iris." Oxford Dictionary of Rhymes. . Retrieved August 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/iris-1