'old-hearted' originates from the combination of 'old' and 'hearted', where 'old' refers to something aged or from the past, and 'hearted' implies having a certain disposition or attitude.

'Old-hearted' combines the Middle English word 'olde' and the Old English 'heorte', eventually forming the modern English word 'old-hearted'.

Initially, it meant 'having the heart or spirit of an older person', but over time it evolved into its current meaning of 'having an old-fashioned mindset'.