alkali
UK: ˈælkəlaɪ | US: ˈælkəˌlaɪ
n. A chemical substance that neutralizes acids, typically with a bitter taste and slippery feel (e.g., sodium hydroxide).
n. (Geology) A soluble mineral salt found in arid soils.
The word "alkali" traces back to Arabic al-qalīy (القلي), meaning "the ashes (of saltwort plants)." Saltwort ashes were historically used to produce soda ash (sodium carbonate), an early alkali. The term entered Medieval Latin as alkali and later spread to European languages, retaining its core meaning of a base substance that neutralizes acids. The morpheme al- is the Arabic definite article "the," while kali refers to "ashes," reflecting the word’s practical origins in early chemistry.
Sodium hydroxide is a strong alkali used in soap production.
The soil’s high alkali content makes it unsuitable for farming.
Vinegar can neutralize an alkali like baking soda.
Ancient Egyptians extracted alkali from plant ashes for glassmaking.
Testing the pH revealed the solution was highly alkaline.