'acetylaniline' originates from 'acetyl' and 'aniline', where 'acetyl' is derived from the Latin 'acetum' meaning 'vinegar', and 'aniline' is derived from the Portuguese 'anil' meaning 'indigo'.

'acetyl' changed from the Latin word 'acetum' and 'aniline' from the Portuguese word 'anil', eventually forming the modern English word 'acetylaniline'.

Initially, it meant 'a compound related to vinegar and indigo', but over time it evolved into its current meaning of 'a chemical compound derived from aniline'.