'apyretic' originates from New Latin/Greek, specifically from the privative prefix 'a-' and the Greek word 'pyretos', where 'a-' meant 'not' and 'pyretos' meant 'fever'.

'apyretic' changed from the New Latin word 'apyreticus' and was adopted into modern English medical vocabulary as 'apyretic'.

Initially, it meant 'not feverish', and over time this meaning has remained essentially the same in medical usage.