adjective
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Capable of neutralizing an acid. Bases are alkaline.
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Relating to an alkali compound.
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Having a pH greater than 7.
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Having a relatively low concentration of hydrogen ions.
Etymology
Origin of alkaline
Vocabulary lists containing alkaline
Chemistry - High School
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Chemistry - Middle School
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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.
“When the Emperor Was Divine” takes place in Utah, in “a city of tar-paper barracks behind a barbed-wire fence on a dusty alkaline plain.”
From The Wall Street Journal • Feb. 17, 2026
The site's pH of 12 makes it one of the most alkaline environments ever documented, creating conditions that are exceptionally difficult for life to endure.
From Science Daily • Nov. 9, 2025
The results were all over the map, but at least one finding was consistent: All but one of the properties showed evidence of high pH, or increased alkalinity, likely because ash is highly alkaline.
From Los Angeles Times • Apr. 24, 2025
The liquid is believed to be a type of home-made chilli spray with no strong acid or alkaline ingredients, police added.
From BBC • Feb. 18, 2025
When the soil is too alkaline, which can be thought of as being too sweet, you need to add sulfur.
From "Counting by 7s" by Holly Goldberg Sloan
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.