'alkali-sensitive' originates from modern English as a compound of 'alkali' and 'sensitive'. 'alkali' ultimately comes from Arabic, specifically the word 'al-qaliy' meaning 'ashes (of saltwort)'; 'sensitive' comes from Latin, specifically the word 'sensitivus' meaning 'capable of feeling or perception'.

'alkali' came into European languages via Medieval Latin/Spanish/Italian from Arabic 'al-qaliy' and entered English as 'alkali'. 'sensitive' passed from Latin 'sensitivus' into Old French 'sensitif' and Middle English 'sensitive'; the compound 'alkali-sensitive' is a modern English formation combining these elements.

Originally, 'alkali' referred to plant ashes used in making soda/lye and 'sensitive' meant 'capable of sensation'; over time 'alkali' came to mean substances with basic (high pH) chemical properties and 'sensitive' broadened to mean 'easily affected', yielding the current sense 'easily affected by alkali'.