'antipyretic' originates from Greek, specifically the word 'antipyrētikos', where 'anti-' meant 'against' and 'pyret-' (from Greek 'pyretos') meant 'fever'.

'antipyretic' came into English via Late/Modern Latin ('antipyreticus' / 'antipyrētikos') and was adopted into English with essentially the same form and meaning.

Initially it literally meant 'against fever'; over time it came to denote specifically 'a substance or an agent that reduces fever' or the property of reducing fever.