a chemical substance that reacts with acids to form a salt and gives a solution with a pH of more than seven when it is dissolved in watercompareacidWord Originlate Middle English (denoting a saline substance derived from the ashes of various plants, including glasswort, a salt-marsh plant formerly used to make glass): from medieval Latin, from Arabic al-qalī ‘calcined ashes (of the glasswort etc.), reduced through exposure to strong heat’, from qalā ‘fry, roast’.
See alkali in the Oxford Learner's Dictionary of Academic EnglishSee alkali in the Oxford Advanced American Dictionary
