Meaning of ALKALI in English

n. (pl. alkalis) 1 a any of a class of substances that liberate hydroxide ions in water, usu. form caustic or corrosive solutions, turn litmus blue, and have a pH of more than 7, e.g. caustic soda. b any other substance with similar but weaker properties, e.g. sodium carbonate. 2 Chem. any substance that reacts with or neutralizes hydrogen ions. alkali metals any of the univalent group of metals, lithium, sodium, potassium, rubidium, and caesium, whose hydroxides are alkalis. alkalimeter n. alkalimetry n.

[ ME f. med.L, f. Arab. al-kali calcined ashes f. kala fry ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.