'alkalise' originates from Arabic, specifically the word 'al-qalī', where 'al-' meant 'the' and 'qalī' meant 'ashes of the saltwort plant'.

'al-qalī' transformed into the Medieval Latin word 'alkali', and eventually became the modern English word 'alkalise' through Middle English.

Initially, it meant 'ashes of the saltwort plant', but over time it evolved into its current meaning of 'to make or become alkaline'.