Meaning of ALKALI in English

[] n, pl -lies or -lis [ME, fr. ML, fr. Ar al-qili the ashes of the plant saltwort] (14c) 1: a soluble salt obtained from the ashes of plants and consisting largely of potassium or sodium carbonate; broadly: a substance (as a hydroxide or carbonate of an alkali metal) having marked basic properties--compare base 7a

2: alkali metal

3: a soluble salt or a mixture of soluble salts present in some soils of arid regions in quantity detrimental to agriculture

Merriam-Webster English vocab.      Английский словарь Merriam Webster.