'croon' originates from Middle Dutch, specifically the word 'kronen', where 'kronen' meant 'to groan or lament softly'.

'kronen' changed from the Middle Dutch word 'kronen' and eventually became the modern English word 'croon'.

Initially, it meant 'to groan or lament softly', but over time it evolved into its current meaning of 'to sing softly or hum'.