sodium hydroxide

American

noun

Chemistry.

a white, deliquescent, water-soluble solid, NaOH, usually in the form of lumps, sticks, chips, or pellets, that upon solution in water generates heat: used chiefly in the manufacture of other chemicals, rayon, film, soap, as a laboratory reagent, and in medicine as a caustic.

sodium hydroxide British

noun

Also called: caustic soda. a white deliquescent strongly alkaline solid used in the manufacture of rayon, paper, aluminium, soap, and sodium compounds. Formula: NaOH See also lye

"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

sodium hydroxide Scientific

A white, corrosive, solid compound that absorbs water and carbon dioxide from the atmosphere and forms lye when in solution. Sodium hydroxide is toxic and strongly alkaline and is used to make chemicals and soaps and to refine petroleum. Chemical formula: NaOH.

Etymology

Origin of sodium hydroxide

First recorded in 1880–85

Compare meaning

How does sodium-hydroxide compare to similar and commonly confused words? Explore the most common comparisons:

potassium hydroxide vs. sodium hydroxide

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

sodium hydroxide

White liquor is an alkaline chemical containing sodium hydroxide and sodium sulfide.

From BBC ● May 26, 2026

Monday in the area of Low Line and Magnolia roads in Morgan County and the nine derailed cars contained dry cement, calcium chloride and sodium hydroxide, according to CSX and county officials.

From Seattle Times ● Feb. 13, 2024

The team treated the fruiting bodies of enoki mushrooms and the inedible reishi mushrooms with sodium hydroxide and hydrogen peroxide.

From Science Daily ● Jan. 8, 2024

He is leading a project to study the effects of pouring tons of alkaline sodium hydroxide into the ocean off the New England coast.

From Science Magazine ● Nov. 30, 2023

This is due to the fact that the salt hydrolyzes in solution into sodium hydroxide and disodium phosphate, as represented in the equation Na3PO4 + H2O = Na2HPO4 + NaOH.

From An Elementary Study of Chemistry by McPherson, William

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023