Definition of alkaline

The word "alkaline" traces back to the Arabic word "al-qali," meaning "the ashes" or "the calx." This refers to the ashes of certain plants, like saltwort, which were historically used to make alkaline solutions. The term "alkali" was later adopted into Latin and English, evolving into "alkaline" to describe substances having the properties of these plant ashes, specifically a high pH and a bitter taste.