[lith-ee-uh m]


Chemistry. a soft, silver-white metallic element, the lightest of all metals, occurring combined in certain minerals. Symbol: Li; atomic weight: 6.939; atomic number: 3; specific gravity: 0.53 at 20°C.
Pharmacology. the substance in its carbonate or citrate form used in the treatment or prophylaxis of bipolar disorder or mania.

Origin of lithium

From New Latin, dating back to 1810–20; see origin at lith-, -ium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for lithium

Contemporary Examples of lithium

Historical Examples of lithium

  • The writer has no experience of the bromide of lithium (Bartholow).

  • Lithium is absent, and Sodium is only present in very minute quantity.


    G. F. Rodwell

  • Random samplings from various parts of the area show that the ash consists of magnesium, lithium, and beryllium carbonates.

    Anything You Can Do ...

    Gordon Randall Garrett

  • Nor had he tried to steal any of the fusion materials—the heavy isotopes of hydrogen or any of the lithium isotopes.

    Anything You Can Do ...

    Gordon Randall Garrett

  • He has shown apparently that lithium, when acted upon by radium emanations, changes to some extent to copper.

    The Popes and Science

    James J. Walsh

British Dictionary definitions for lithium



a soft silvery element of the alkali metal series: the lightest known metal, used as an alloy hardener, as a reducing agent, and in batteries. Symbol: Li; atomic no: 3; atomic wt: 6.941; valency: 1; relative density: 0.534; melting pt: 180.6°C; boiling pt: 1342°C

Word Origin for lithium

C19: New Latin, from litho- + -ium
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 lithium

silver-white metallic element, 1818, with element ending -ium + lithia, Modern Latin name given by Swedish chemist Jöns Jacob Berzelius (1779-1848) to the earth from which it was extracted, from Greek lithos "stone" (see litho-). So called from its mineral origin and to distinguish it from two previously known alkalis of vegetable origin.

Online Etymology Dictionary, © 2010 Douglas Harper

lithium in Medicine



n. Symbol Li

A soft, highly reactive metallic element whose carbonate form is used in psychopharmacology. Atomic number 3.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

lithium in Science




A soft, silvery metallic element of the alkali group that occurs in small amounts in some minerals. It is the lightest of all metals and is highly reactive. Lithium is used to make alloys, batteries, glass for large telescopes, and ceramics. Atomic number 3; atomic weight 6.941; melting point 179°C; boiling point 1,317°C; specific gravity 0.534; valence 1. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.