|one of the minute, coiled, tubular glands of the skin that secrete sweat|
|either one of the second pair of cranial nerves, consisting of sensory fibers that conduct impulses from the retina to the brain|
|—n , pl irises, irides|
|1.||the coloured muscular diaphragm that surrounds and controls the size of the pupil|
|2.||flag orris See also stinking iris Also called: fleur-de-lys any plant of the iridaceous genus Iris, having brightly coloured flowers composed of three petals and three drooping sepals|
|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|
|[C14: from Latin: rainbow, iris (flower), crystal, from Greek]|
iris i·ris (ī'rĭs)
n. pl. i·ris·es or i·ri·des (ī'rĭ-dēz', ĭr'ĭ-)
The round pigmented contractile membrane of the eye that is perforated in the center by the pupil, forms the front part of the vascular tunic, and is attached on the margin to the ciliary body.
|iris (ī'rĭs) Pronunciation Key
Plural irises or irides (ī'rĭ-dēz', ĭr'ĭ-)
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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in Greek mythology, the personification of the rainbow and (in Homer's Iliad, for example) a messenger of the gods. According to the Greek poet Hesiod, she was the daughter of Thaumas and the ocean nymph Electra. In Hesiod's works, at least, she had the additional duty of carrying water from the River Styx in a ewer whenever the gods had to take a solemn oath. The water would render unconscious for one year any god or goddess who lied. In art, Iris was normally portrayed with wings, and her attributes were the herald's staff and a vase. She was shown serving wine to the gods or escorting them to the wedding of Peleus and Thetis.
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