'attemperate' originates from Latin, specifically the verb 'adtemperare', where 'ad-' meant 'to' and 'temperare' meant 'to temper, mix or regulate'.

'adtemperare' passed into Late Latin/Medieval Latin as 'adtemperare'/'adtemperatus', entered Middle English in forms such as 'attemperaten' and eventually became the modern English 'attemperate' and its derivative 'attemperately'.

Initially it meant 'to bring into proper measure or temper' in a literal or figurative sense; over time it has been used chiefly in the figurative sense 'to moderate or adjust', a meaning retained in modern usage.