lithium

noun

lith·​i·​um ˈli-thē-əm 

1

: a chemical element of the alkali metal group that is the lightest metal known and that is used especially in alloys and glass, in mechanical lubricants, and in storage batteries see Chemical Elements Table

2

: a salt of lithium (such as lithium carbonate) used in psychiatric medicine

Examples of lithium in a Sentence

Recent Examples on the Web

Realization of high-performance lithium sulfur batteries The research team revealed that the results of this study could contribute to the realization of high-performance lithium sulfur batteries for diverse real-life applications. —Prabhat Ranjan Mishra, Interesting Engineering, 8 Nov. 2025

Earlier this year, Southwest Airlines implemented new restrictions on lithium batteries prohibiting them from being used while inside bags. —Colson Thayer, PEOPLE, 7 Nov. 2025

Rare earths, lithium, and semiconductors provide the most value when processed through a domestic loop of mining, refining, manufacturing, assembly, and fabrication. —Shilpan Amin, Fortune, 5 Nov. 2025

Standard and optional features to be offered for the trailer build will include a lithium battery, inverter, 18-L compressor fridge and water system with 10-L canister and electric pump. —New Atlas, 28 Oct. 2025

Word History

Etymology

borrowed from New Latin (in German context) Lithium, taken as the metallic component of the alkali Lithion, probably based on Greek litheîon, neuter of litheîos "of stone," derivative of líthos "stone, rock," of obscure origin

Note: The alkali was discovered and analyzed, apparently in late 1817, by the Swedish chemist Johan August Arfwedson (1792-1841), who at the time was working in the Stockholm laboratory of J.J. berzelius. Berzelius reported on the discovery and named the components in letters written to the editors of learned publications, as J. S. C. Schweiggers' Journal für Chemie und Physik. Schweiggers published the letter, dated January 27, 1818, as "Ein neues mineralisches Alkali und ein Neues Metall" ("a new mineral alkali and a new metal") in vol. 21 of the journal (pp. 44-48). According to Berzelius, "we have named it [the new alkali] Lithion, thereby alluding to its first discovery in the mineral kingdom, as the two others [the alkali metals sodium and potassium] were first discovered in organic substances [literally, "organic nature"]. Its radical will then be named Lithium." ("Wir haben es Lithion genannt, um dadurch auf seine erste Entdeckung im Mineralreich anzuspielen, da die beiden anderen erst in der organischen Natur entdeckt wurden. Sein Radical wird dann Lithium genannt werden.")

First Known Use

1818, in the meaning defined at sense 1

Phrases Containing lithium

• lithium carbonate
• lithium fluoride
• lithium-ion battery
• lithium niobate

Rhymes for lithium

• pythium

Kids Definition

lithium

noun

lith·​i·​um ˈlith-ē-əm 

: a soft silver-white element that is the lightest metal known see element

Medical Definition

lithium

noun

lith·​i·​um ˈlith-ē-əm 

1

: a soft silver-white element of the alkali metal group that is the lightest metal known and that is used in chemical synthesis and in storage batteries

—symbol Li see Chemical Elements Table

2

: a lithium salt and especially lithium carbonate used in psychiatric medicine