'aniline' originates from Portuguese, specifically the word 'anil', where 'anil' meant 'indigo', combined with the chemical suffix '-ine' meaning 'of or relating to (used in names of organic compounds)'.

'anil' came via Arabic 'an-nīl' (the indigo), from Persian 'nīl', from Sanskrit 'nīla'; in the 19th century German 'Anilin' was formed from 'anil' + '-in', and this eventually became the modern English word 'aniline'.

Initially, it referred to a substance derived from indigo; over time it came to denote the specific aromatic amine 'C6H5NH2' and, by extension in plural, compounds of the aniline class.