'alkali' definitions:

Definition of 'alkali'

(from WordNet)
noun
Any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water; "bases include oxides and hydroxides of metals and ammonia" [syn: base, alkali]
noun
A mixture of soluble salts found in arid soils and some bodies of water; detrimental to agriculture

Synonyms of 'alkali'

From: Moby Thesaurus