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

The model is based on how lithium ions propagate through a battery’s electrodes, similar to how caffeine molecules dissolve from coffee grounds. —ArsTechnica, 28 Apr. 2026

Sodium is far more abundant than lithium and is not concentrated in a handful of geopolitically sensitive regions. —Omar Kardoudi april 28, New Atlas, 28 Apr. 2026

The new process targets key battery materials including lithium, cobalt, nickel, and manganese, which are in growing demand as electric vehicle and electronics production expands worldwide. —Neetika Walter, Interesting Engineering, 27 Apr. 2026

In 2025 alone, there were 97 lithium battery incidents on aircraft, with 82 involving passenger planes and 34 involving batteries or battery packs, according to FAA data. —Kelly McCarthy, ABC News, 27 Apr. 2026

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