| iridious | <chemistry> Of or pertaining to iridium; applied specifically to compounds in which iridium has a low valence. Source: Websters Dictionary (01 Mar 1998) |
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| iridium | <chemistry, element> A rare metallic element, of the same group as platinum, which it much resembles, being silver-white, but harder, and brittle, and indifferent to most corrosive agents. With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Iridium usually occurs as a native alloy with osmium (iridosmine or osmiridium), which may occur alone or with platinum. Iridium, as an alloy with platinum, is used in bushing the vents of heavy ordnance. It is also used for the points of gold pens, and in a finely powdered condition (iridium black), for painting porcelain black. Atomic weight: 192.5 Abbreviation: Ir Origin: NL, fr. L. Iris, iridis, the rainbow. So called from the iridescence of some of its solutions. See Iris. (30 Mar 1998) |
| iridium radioisotopes | Unstable isotopes of iridium that decay or disintegrate emitting radiation. Ir atoms with atomic weights 182-190, 192, and 194-198 are radioactive iridium isotopes. (12 Dec 1998) |
| irido- | Irid- The iris. Origin: G. Iris (irid-), rainbow (05 Mar 2000) |
| iridoavulsion | Avulsion, or tearing away, of the iris. (05 Mar 2000) |
| iridocele | Herniation of a portion of the iris through a corneal defect. Origin: irido-+ G. Kele, hernia (05 Mar 2000) |
| iridochoroiditis | Inflammation of both iris and choroid. (05 Mar 2000) |
| iridocoloboma | A coloboma or congenital defect of the iris. Origin: irido-+ G. Koloboma, coloboma (05 Mar 2000) |
| iridocorneal | Relating to the iris and the cornea. (05 Mar 2000) |
| iridocorneal angle | The acute angle between the iris and the cornea at the periphery of the anterior chamber of the eye. Synonym: angulus iridocornealis, angle of iris, angulus iridis, filtration angle. (05 Mar 2000) |
| iridocorneal endothelial syndrome | <syndrome> Syndrome of glaucoma, iris atrophy, decreased corneal endothelium, anterior peripheral synechia, and multiple iris nodules. Synonym: Cogan-Reese syndrome, iris-nevus syndrome. (05 Mar 2000) |
| iridocorneal mesodermal dysgenesis | Mesodermal dysgenesis of cornea and iris, producing pupillary anomalies, posterior embryotoxon, and secondary glaucoma. Synonym: Rieger's anomaly. (05 Mar 2000) |
| iridocorneal syndrome | <syndrome> Iris atrophy with corneal oedema. Synonym: iridocorneal syndrome. (05 Mar 2000) |
| iridocyclectomy | Removal of the iris and ciliary body for excision of a tumour. Origin: irido-+ G. Kyklos, circle (ciliary body), + ektome, excision (05 Mar 2000) |
| iridocyclitis | <ophthalmology> Inflammation of the iris and of the ciliary body, anterior uveitis. (18 Nov 1997) |