'windproof' originates from Modern English, specifically formed from the words 'wind' and 'proof', where 'wind' meant 'moving air' and 'proof' meant 'resistant to' or 'able to withstand'.

'proof' developed from Old French 'preuve' (noun) and from Latin 'probare' meaning 'to test' or 'to prove'; the sense of 'proof' as a combining element meaning 'resistant to' arose in Late Middle English, and 'windproof' was formed as a compound in Modern English.

Initially, 'proof' carried the idea of being 'tested' or 'proven'; over time in compounds like 'windproof' it shifted to the sense 'resistant to or protecting against', leading to the current meaning 'resists wind'.