'non-light-dependent' is a modern compound formed from the prefix 'non-' (from Latin 'non', meaning 'not'), the noun 'light' (from Old English 'lēoht'/'lēoht', meaning 'visible radiance'), and 'dependent' (from Latin 'dependere' via Old French 'dependant', meaning 'to hang down; to be determined by').

'light' comes from Old English 'lēoht' (Middle English 'light'), and 'dependent' comes from Latin 'dependere' -> Old French 'dependant' -> Middle English 'dependent'; the negative prefix 'non-' has long been used in English to form negating compounds, yielding the modern compound 'non-light-dependent'.

Initially the components separately meant 'not' + 'light' + 'to hang/be determined by'; over time they combined in English to form the adjectival compound meaning 'not requiring light' or 'independent of light'.