'pure-hearted' originates from the combination of 'pure' and 'heart,' where 'pure' meant 'free from contamination' and 'heart' referred to the emotional or moral nature of a person.

'pure-hearted' evolved from the Old English word 'heorte' meaning 'heart' and the Latin word 'purus' meaning 'clean or untainted,' eventually forming the modern English term 'pure-hearted.'

Initially, it meant 'having a clean or untainted heart,' and this meaning has largely remained the same in modern usage.