alkali

[ al-kuh-lahy ]
/ ˈæl kəˌlaɪ /

noun, plural al·ka·lis, al·ka·lies.

Chemistry.
  1. any of various bases, the hydroxides of the alkali metals and of ammonium, that neutralize acids to form salts and turn red litmus paper blue.
  2. any of various other more or less active bases, as calcium hydroxide.
  3. (not in technical use) an alkali metal.
  4. Obsolete. any of various other compounds, as the carbonates of sodium and potassium.
Agriculture. a soluble mineral salt or a mixture of soluble salts, present in some soils, especially in arid regions, and detrimental to the growing of most crops.

adjective

Chemistry. alkaline.

RELATED WORDS

Origin of alkali

1300–50; Middle English alkaly < Middle French alcali < dialectal Arabic al-qalī, variant of Arabic qily saltwort ashes
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for alkali

British Dictionary definitions for alkali

alkali

/ (ˈælkəˌlaɪ) /

noun plural -lis or -lies

chem a soluble base or a solution of a base
a soluble mineral salt that occurs in arid soils and some natural waters

Word Origin for alkali

C14: from Medieval Latin, from Arabic al-qili the ashes (of the plant saltwort)
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

Medicine definitions for alkali

alkali

[ ălkə-lī′ ]

n. pl. al•ka•lis

A carbonate or hydroxide of an alkali metal, the aqueous solution of which is bitter, slippery, caustic, and characteristically basic in reactions.
Any of various soluble mineral salts found in natural water and arid soils.
Alkali metal.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for alkali

alkali

[ ălkə-lī′ ]

Plural alkalis alkalies

A hydroxide of an alkali metal. The aqueous solution of alkalis is bitter, slippery, caustic, and characteristically basic in reactions.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for alkali

alkali

[ (al-kuh-leye) ]

A bitter, caustic mineral often found in large beds in the desert. Alkalis are bases; two common examples are lye and ammonia.

Note

Plants have difficulty growing in soil that is rich in alkalis.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.