'closely-divided' originates from the combination of 'close' and 'divide', where 'close' meant 'near' and 'divide' meant 'to separate into parts'.

'close' and 'divide' were used separately in Middle English and eventually combined to form the modern English term 'closely-divided'.

Initially, it meant 'to separate into parts that are near each other', but over time it evolved into its current meaning of 'almost equally split'.