'pile-up' originates from the English word 'pile,' which means 'a heap or stack,' combined with 'up,' indicating an upward or increased state.

'pile' changed from the Old English word 'pīl,' meaning 'stake or post,' and eventually became the modern English word 'pile' through Middle English.

Initially, it meant 'to heap or stack,' but over time it evolved into its current meaning of 'a traffic accident involving several vehicles.'