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

Soap combines fats or oils with sodium hydroxide (in the case of soap bars) or potassium hydroxide (for liquid soap). —Matt Fuchs, TIME, 3 Mar. 2025

This chemically rearranges seawater molecules (hydrogen, oxygen, and sodium chloride) based on their constituent ions’ charge, resulting in the production of an acid (hydrochloric acid) and a base (sodium hydroxide). —IEEE Spectrum, 26 Dec. 2024

On one tray lay a small mountain of crystal flakes that the main cook said was sodium hydroxide, a fentanyl ingredient. —Meridith Kohut, New York Times, 29 Dec. 2024

The substance is found in products such as brake linings and gaskets and is used to manufacture chlorine bleach and sodium hydroxide, also known as caustic soda, including some that is used for water purification. —Matthew Daly, San Diego Union-Tribune, 18 Mar. 2024

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