'non-phototaxis' originates from a combination of the prefix 'non-' and the term 'phototaxis'. 'non-' comes from Latin 'non' meaning 'not', while 'photo-' derives from Greek 'phōtós' (φῶς) meaning 'light' and 'taxis' (τάξις) meaning 'arrangement' or 'ordered movement'.

'phototaxis' was formed in scientific/biological English from Greek roots 'phōtós' + 'taxis' (used in New Latin and modern scientific coinage). The negative prefix 'non-' was later attached in modern English usage to indicate absence, producing 'non-phototaxis'.

Originally 'taxis' meant 'arrangement' or 'order' in Greek; in biological usage it came to mean 'directed movement' or 'orientation'. 'Non-phototaxis' therefore initially and consistently denotes the absence of light-directed movement.