sodium hydroxide

noun

: a white brittle solid NaOH that is a strong caustic base used especially in making soap, rayon, and paper

Examples of sodium hydroxide in a Sentence

Recent Examples on the Web

These water-rock interactions release sodium hydroxide (NaOH) into the ocean that subsequently reacts with carbon dioxide and produces the high alkalinity. —Keith Cooper, Space.com, 8 July 2025

While use of chrysotile asbestos was on the decline, the dangerous mineral has lingered in various gaskets, brake blocks, aftermarket automotive brakes and linings, other vehicle friction products, and some diaphragms used to make sodium hydroxide and chlorine. —ArsTechnica, 17 June 2025

Importantly, those supports – and only those supports – dissolve within 15 minutes when the object is subsequently immersed in a sodium hydroxide (aka lye) solution. —Ben Coxworth, New Atlas, 4 June 2025

The natural oils are then mixed with either potassium hydroxide to create a liquid soap or sodium hydroxide to create a solid soap. —Patricia Shannon, Southern Living, 27 May 2025

Word History

First Known Use

1885, in the meaning defined above

Rhymes for sodium hydroxide

• monoxide
• tetroxide

Kids Definition

sodium hydroxide

noun

: a white brittle solid that is strongly alkaline and is used especially in making soap, rayon, and paper

Medical Definition

sodium hydroxide

noun

: a white brittle deliquescent solid NaOH that dissolves readily in water to form a strongly alkaline and caustic solution and that is used in pharmacy as an alkalizing agent

called also caustic soda