'aniline-affine' is a compound formed from 'aniline' and 'affine'. 'Aniline' originates from Portuguese 'anil' (from Arabic/Spanish roots referring to the indigo dye), where the element 'anil' referred to indigo-derived substances; 'affine' comes from Latin 'affinis' via French 'affine', meaning 'related' or 'having affinity'.

'aniline' entered scientific English in the 19th century from French/Portuguese naming related to indigo ('anil') and the chemical suffix '-ine'; 'affine' evolved from Latin 'affinis' through Old French and later English use. In modern technical English the two elements are combined as a descriptive compound 'aniline-affine' to denote affinity toward aniline.

Initially, 'aniline' referred specifically to substances derived from indigo dye and later to the particular aromatic amine known as aniline; 'affine' originally meant 'neighboring' or 'connected' and shifted toward the sense 'having affinity'. Together they now mean 'having an affinity for aniline.'