'anisotropic' originates from Greek, specifically the word 'anisos,' where 'an-' meant 'not' and 'isos' meant 'equal,' combined with 'tropos' meaning 'turn.'

'anisos' combined with 'tropos' in Greek, and eventually became the modern English word 'anisotropic.'

Initially, it meant 'not equal in all directions,' and this meaning has largely remained the same in modern usage.