'heartless' originates from Old English, specifically the word 'heortleas,' where 'heort' meant 'heart' and '-leas' meant 'without.'

'heortleas' transformed into the Middle English word 'herteles,' and eventually became the modern English word 'heartless.'

Initially, it meant 'without heart or courage,' but over time it evolved into its current meaning of 'lacking compassion or empathy.'