'anisotropous' originates from Greek, specifically the word 'anisotropos', where 'a-' meant 'not', 'iso-' meant 'equal', and 'tropos' meant 'turn' or 'direction'.

'anisotropous' entered scientific usage via New Latin and 19th-century scientific literature (including German and English), derived from Greek 'anisotropos' and related to the noun 'anisotropy'.

Initially it meant 'not the same in every direction'; over time this basic meaning has remained stable and is preserved in modern scientific usage.