'lightless' originates from Old English, specifically the word 'lēohtlēas,' where 'lēoht' meant 'light' and 'lēas' meant 'without.'

'lēohtlēas' transformed into the Middle English word 'lightles,' and eventually became the modern English word 'lightless.'

Initially, it meant 'without light,' and this meaning has largely remained the same in modern usage.