a rare, metallic chemical element that is a silver-white solid or a gray-to-black powder, used in thermocouples, electrodes, etc.: symbol, Re; at. no., 75
See rhenium in American Heritage Dictionary 4
(rēˈnē-əm)
noun Symbol Re
A rare, dense, silvery-white metallic element with a very high melting point used for electrical contacts and with tungsten for high-temperature thermocouples. Atomic number 75; atomic weight 186.2; melting point 3,180°C; boiling point 5,627°C; specific gravity 21.02; valence 1, 2, 3, 4, 5, 6, 7. See Table at element.