'non-aqueous' originates from English, specifically the prefix 'non-' and the adjective 'aqueous', where 'non-' meant 'not' and 'aqueous' ultimately comes from Latin 'aqua' meaning 'water'.

'aqueous' developed from Latin 'aqua' with the adjectival suffix '-eus' (Late Latin/Medieval Latin forms such as 'aqueōsus'/'aqueus'), passed into Middle English as 'aqueous'; the negative prefix 'non-' (from Old English/Proto-Germanic negation elements) was later attached in modern English to form the compound 'non-aqueous'.

Initially, 'aqueous' meant 'relating to or containing water', so 'non-aqueous' simply meant 'not watery'; over time the term became specialized (especially in chemistry) to mean 'without water' or 'in a solvent other than water'.