Definitions for iridiumɪˈrɪd i əm
Random House Webster's College Dictionary
i•rid•i•umɪˈrɪd i əm(n.)
a precious metallic element resembling platinum: used in alloys.
Ref: Symbol: Ir; 3
Origin of iridium:
1804; < L īrid-, s. of īris rainbow (see iris ) + -ium2; so named from its iridescence when dissolved in hydrochloric acid
iridium, Ir, atomic number 77(noun)
a heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium
A metallic chemical element (symbol Ir) with an atomic number of 77.
Origin: ἶρις (because of the bright colour of many of iridium's salts)
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. Symbol Ir. Atomic weight 192.5
The Nuttall Encyclopedia
a metallic elementary body of rare occurrence, and found in the ores of platinum.
U.S. National Library of Medicine
A metallic element with the atomic symbol Ir, atomic number 77, and atomic weight 192.22.