Meaning of platiniridium

plat•in•i•rid•i•um

Pronunciation: (plat"n-i-rid'ē-um, -ī-rid'-), [key]
— n.
  1. a natural alloy composed chiefly of platinum and iridium.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.