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1. Any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water
   "alkalis include oxides and hydroxides of metals and ammonia"
   - base
    
2. A mixture of soluble salts found in arid soils and some bodies of water; detrimental to agriculture

Derived forms: alkalis, alkalies

See also: alkalic, alkalize

Type of: chemical compound, compound, salt

Encyclopedia: Alkali