'anil' originates from Portuguese and Spanish, specifically the word 'anil' (Spanish 'añil'), from Arabic 'an-nīl,' via Persian 'nīl,' ultimately from Sanskrit 'nīla,' where 'nīla' meant 'dark blue; indigo'.

'anil' changed from Spanish 'añil' and Portuguese 'anil' (from Arabic 'an-nīl'), and eventually became the modern English word 'anil'.

Initially, it meant 'indigo (the dye/plant)', but later also developed the technical chemical sense 'aniline-derived imine'.