'slow-growing' originates from the combination of 'slow' and 'growing', where 'slow' meant 'not quick' and 'growing' meant 'increasing in size'.

'slow-growing' changed from the Old English word 'slāw' and the Middle English word 'growen', eventually becoming the modern English word 'slow-growing'.

Initially, it meant 'increasing in size at a slow pace', and this meaning has largely remained the same in modern usage.