cobalt

[ koh-bawlt ]
/ ˈkoʊ bɔlt /

noun

a silver-white metallic element with a faint pinkish tinge, occurring in compounds whose silicates afford important blue coloring substances for ceramics. Symbol: Co; atomic weight: 58.933; atomic number: 27; specific gravity: 8.9 at 20°C.

Nearby words

  1. cob coal,
  2. cob money,
  3. cob pie,
  4. cobaea,
  5. cobalamin,
  6. cobalt 60,
  7. cobalt bloom,
  8. cobalt blue,
  9. cobalt bomb,
  10. cobalt green

Origin of cobalt

1675–85; < German Kobalt, variant of Kobold kobold

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

Examples from the Web for cobalt


British Dictionary definitions for cobalt

cobalt

/ (ˈkəʊbɔːlt) /

noun

a brittle hard silvery-white element that is a ferromagnetic metal: occurs principally in cobaltite and smaltite and is widely used in alloys. The radioisotope cobalt-60, with a half-life of 5.3 years, is used in radiotherapy and as a tracer. Symbol: Co; atomic no: 27; atomic wt: 58.93320; valency: 2 or 3; relative density: 8.9; melting pt: 1495°C; boiling pt: 2928°C

Word Origin for cobalt

C17: German Kobalt, from Middle High German kobolt goblin; from the miners' belief that malicious goblins placed it in the silver ore

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 cobalt

cobalt

n.

1680s, from German kobold "household goblin," Harz Mountains silver miners' term for rock laced with arsenic and sulfur (so called because it degraded the ore and made the miners ill), from Middle High German kobe "hut, shed" + *holt "goblin," from hold "gracious, friendly," a euphemistic word for a troublesome being. The metallic element was extracted from this rock. It was known to Paracelsus, but discovery is usually credited to the Swede George Brandt (1733), who gave it the name. Extended to a blue color 1835 (a mineral containing it had been used as a blue coloring for glass since 16c.). Cf. nickel.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for cobalt

cobalt

[ kōbôlt′ ]

n. Symbol Co

A metallic element, used chiefly for magnetic and high-temperature alloys and in the form of its salts for blue glass and ceramic pigments. Atomic number 27.

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

Science definitions for cobalt

cobalt

[ kōbôlt′ ]

Co

A silvery-white, hard, brittle metallic element that occurs widely in metal ores. It is used to make magnetic alloys, heat-resistant alloys, and blue pigment for ceramics and glass. Atomic number 27; atomic weight 58.9332; melting point 1,495°C; boiling point 2,900°C; specific gravity 8.9; valence 2, 3. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.