'fever-lowering' originates from Modern English, specifically a compound of 'fever' and the present-participle form 'lowering'. 'Fever' ultimately comes from Latin 'febris' (via Old French 'fièvre' and Old English), and 'lowering' is formed from the verb 'lower' + the participial suffix '-ing'.

'fever' came into English via Old French 'fièvre' from Latin 'febris'; 'lowering' developed from the verb 'lower' (of Old English/Germanic origin) combined with '-ing' to form the present participle, and the two elements were joined in Modern English as a descriptive compound.

Initially, the compound literally meant 'that which lowers a fever'; over time it has remained essentially the same and is used both adjectivally (describing antipyretic effect) and nominally (referring to an antipyretic).