'ground-up' originates from the combination of 'ground' and 'up', where 'ground' is the past participle of 'grind', meaning 'to crush or reduce to powder'.

'ground' changed from Old English 'grindan', meaning 'to crush', and eventually became the modern English word 'ground'.

Initially, it meant 'to crush or reduce to powder', and this meaning has largely remained the same in modern usage.