'remorseless' originates from Middle English, specifically the word 'remorseles,' where 're-' meant 'again' and 'mors' meant 'bite.'

'remorseles' transformed into the modern English word 'remorseless' through the addition of the suffix '-less,' indicating the absence of remorse.

Initially, it meant 'without a bite of conscience,' but over time it evolved into its current meaning of 'merciless or relentless.'