[ roh-dee-uh m ]
/ ˈroʊ di əm /

noun Chemistry.

a silvery-white metallic element of the platinum family, forming salts that give rose-colored solutions: used to electroplate microscopes and instrument parts to prevent corrosion. Symbol: Rh; atomic weight: 102.905; atomic number: 45; specific gravity: 12.5 at 20°C.

Nearby words

  1. rhodesian trypanosomiasis,
  2. rhodesoid,
  3. rhodian,
  4. rhodic,
  5. rhodinal,
  6. rhodo-,
  7. rhodochrosite,
  8. rhododendron,
  9. rhododendron bug,
  10. rhodogenesis

Origin of rhodium

From New Latin, dating back to 1804; see origin at rhod-, -ium

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rhodium

British Dictionary definitions for rhodium


/ (ˈrəʊdɪəm) /


a hard corrosion-resistant silvery-white element of the platinum metal group, occurring free with other platinum metals in alluvial deposits and in nickel ores. It is used as an alloying agent to harden platinum and palladium. Symbol: Rh; atomic no: 45; atomic wt: 102.90550; valency: 2–6; relative density: 12.41; melting pt: 1963±3°C; boiling pt: 3697±100°C

Word Origin for rhodium

C19: New Latin, from Greek rhodon rose, from the pink colour of its compounds

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for rhodium



hard white metallic element, 1804, Modern Latin, coined by its discoverer, English physician William H. Wollaston (1766-1828), and named for the color of solutions containing it, from Greek rhodon "rose" (see rose (n.1)) + metallic element ending -ium.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for rhodium


[ rōdē-əm ]

n. Symbol Rh

A hard durable metallic element. Atomic number 45.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for rhodium


[ rōdē-əm ]


A rare, silvery-white metallic element that is hard, durable, and resistant to acids. It is used as a permanent plating for jewelry and is added to platinum to make high-temperature alloys. Atomic number 45; atomic weight 102.905; melting point 1,966°C; boiling point 3,727°C; specific gravity 12.41; valence 2, 3, 4, 5, 6. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.