Pronunciation: (plat'n-um, plat'num),[key] —n. 1. Chem.a heavy, grayish-white, highly malleable and ductile metallic element, resistant to most chemicals, practically unoxidizable except in the presence of bases, and fusible only at extremely high temperatures: used for making chemical and scientific apparatus, as a catalyst in the oxidation of ammonia to nitric acid, and in jewelry. Symbol: Pt; at. wt.: 195.09; at. no.: 78; sp. gr.: 21.5 at 20°C.
2. a light, metallic gray with very slight bluish tinge when compared with silver.
—adj. 1. made of platinum.
2. Music Slang.(of a recording or record album) having sold a minimum of two million single records or one million LPs.