alkali
     n 1: 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}]
     2: a mixture of soluble salts found in arid soils and some
        bodies of water; detrimental to agriculture
     [also: {alkalies} (pl)]
Source: WordNet® 2.0