alkali

noun

al·​ka·​li ˈal-kə-ˌlī 

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 sense 6a

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

Examples of alkali in a Sentence

Recent Examples on the Web

Borax is an alkali that's good for cutting grease, oil, and dirt. —Caitlin Sole, Better Homes & Gardens, 20 Mar. 2024

Then the company adds the alkali back to the water to neutralize it before release. —IEEE Spectrum, 15 Aug. 2023

Silicates are much hardier, resistant to most acids as well as to alkalis. —Jeanne Huber, Washington Post, 26 May 2023

Baking soda is a mild alkali that's effective at dissolving dirt and grease. —Alicia Chilton, Better Homes & Gardens, 12 Sep. 2022

Word History

Etymology

Middle English, from Medieval Latin, from Arabic al-qili the ashes of the plant saltwort

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing alkali

• alkali metal

Kids Definition

alkali

noun

al·​ka·​li ˈal-kə-ˌlī 

plural alkalies or alkalis

1

: a substance (as a hydroxide) that has a bitter taste and neutralizes acids

2

: alkali metal

3

: a salt or mixture of salts easily dissolved in water and present in some soils of very dry regions

Etymology

Middle English alkali "alkali," from Latin alkali (same meaning), from Arabic al-qili "ashes of a particular plant"

Medical Definition

alkali

noun

al·​ka·​li ˈal-kə-ˌlī 

plural alkalies or alkalis

: a substance (as a hydroxide or carbonate of an alkali metal) having marked basic properties compare base