alkali

noun

al·​ka·​li ˈal-kə-ˌlī How to pronounce alkali (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
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 Some dark chocolate products are Dutch-processed or treated with alkali to improve flavor and appearance. — Ann Pietrangelo, Verywell Health, 10 Mar. 2026 Dutch-processed is best because the alkali used in its production gives the cocoa a richer, deeper hue and smoother taste that’s important for color and flavor intensity. — Christopher Kimball, The Denver Post, 13 Feb. 2025 See All Example Sentences for alkali

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

Time Traveler
The first known use of alkali was in the 14th century

Phrases Containing alkali

Rhymes for alkali

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Browse Nearby Words

alkalescent
alkali
alkali bee
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Cite this Entry

“Alkali.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alkali. Accessed 8 Jul. 2026.

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Kids Definition

alkali

noun
al·​ka·​li ˈal-kə-ˌlī How to pronounce alkali (audio)
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 How to pronounce alkali (audio)
plural alkalies or alkalis
: a substance (as a hydroxide or carbonate of an alkali metal) having marked basic properties compare base

More from Merriam-Webster on alkali

Nglish: Translation of alkali for Spanish Speakers

Britannica.com: Encyclopedia article about alkali

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