alkali

noun al·ka·li \ ˈal-kə-ˌlī \

Updated on: 16 Apr 2018

plural alkalies or alkalis

1 : a soluble salt obtained from the ashes of plants and consisting largely of potassium or sodium carbonate; broadly : a substance (such as a hydroxide or carbonate of an alkali metal) having marked basic properties — compare base 7a

2 : alkali metal

3 : a soluble salt or a mixture of soluble salts present in some soils of arid regions in quantity detrimental to agriculture

See alkali defined for English-language learners

See alkali defined for kids

Recent Examples of alkali from the Web

If the alkali is sodium hydroxide, the result is a hard soap, relatively difficult to dissolve.

— c. claiborne ray, New York Times, "In Your Bathroom, the Scum of the Earth," 6 Apr. 2018
In this case, bleach and alkali can be used to break the molecules down.

— simon cotton, Scientific American, "Nerve Agents: What Are They and How Do They Work?," 9 Mar. 2018
Second, if possible, choose natural cocoa over Dutch processed cocoa, which is treated with an alkali, a compound that neutralizes acid.

— lisa drayer, CNN, "Is dark chocolate healthy?," 8 Mar. 2018
And the alkali mariposa lily and ash meadows blazing star are among the plants that grow only along this river.

— jim robbins, New York Times, "The Amargosa River Defies the Desert," 18 Dec. 2017
The alkali breaks down the body’s proteins and fats.

— jonah engel bromwich, New York Times, "An Alternative to Burial and Cremation Gains Popularity," 19 Oct. 2017
Named for the white alkali deposits left by floodwaters, that storied neighborhood rode the capital’s fortunes through good times and bad.

— debbie arrington, sacbee, "Sacramento’s second oldest home ready for its close-up," 6 Sep. 2017
Altogether, an industry analyst has estimated the Gulf region produces 40 percent of the country’s chlor-alkali and vinyl and about 60 percent of the country’s ethylene, polyethylene, and polypropylene.

— sarah zhang, The Atlantic, "A Chemical Plant Catches Fire After Harvey Flooding," 31 Aug. 2017
Many of these cleaners contain corrosive alkalis, which can have grave effects on your gastrointestinal track and respiratory system if inhaled or ingested.

— lindsey campbell, House Beautiful, "13 Dangerous Household Items You Should Quit Using Immediately," 30 July 2014

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'alkali.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.