The definition of an alkali is a soluble salt that comes from the ashes of plants and is made up of mostly potassium or sodium carbonate.(noun)
Lye and calcium carbonate are each an example of an alkali.
See alkali in Webster's New World College Dictionary
Origin: ME alkaly < Ar al-qily, for al-qili, the ashes (of saltwort) < qalai, to roast in a pan
See alkali in American Heritage Dictionary 4
noun pl. al·ka·lis or al·ka·lies
Origin: Middle English, alkaline substance from calcined plant ashes
Origin: , from Medieval Latin
Origin: , from Arabic al-qily, the ashes, lye, potash
Origin: : al-, the
Origin: + qily, ashes (from qalā, to fry, roast; see qly in Semitic roots).
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