The term 'large-scale' combines 'large,' from Old French 'large,' meaning 'broad, wide,' and 'scale,' from Latin 'scala,' meaning 'ladder, staircase.'

'Large' and 'scale' were combined in English to describe something extensive or involving many elements.

Initially, 'scale' referred to a ladder or staircase, but in combination with 'large,' it evolved to describe the extent or magnitude of an operation or event.