'acetylfluoride' originates from the combination of 'acetyl' and 'fluoride', where 'acetyl' refers to the acetyl group (CH₃CO) and 'fluoride' refers to the presence of a fluorine atom.

'acetylfluoride' was formed by combining the terms 'acetyl' and 'fluoride' to describe a compound containing both an acetyl group and a fluorine atom.

Initially, it meant a compound containing an acetyl group and a fluorine atom, and this meaning has remained consistent in modern usage.