'afebrility' originates from English formation based on 'afebrile', where the prefix 'a-' meant 'not' and Latin 'febris' meant 'fever'.

'afebrility' was formed in English from the adjective 'afebrile' (derived from Latin 'febris') by adding the nominalizing suffix '-ity', producing the modern noun 'afebrility'.

Initially it meant 'the state or condition of being without fever', and this meaning has largely remained the same in modern usage.