'airtight' originates from English, specifically the word 'air' combined with 'tight', where 'air' meant 'the invisible gaseous substance surrounding the earth' and 'tight' meant 'closely constrained'.

'airtight' changed from the Old English word 'tīht' meaning 'tight' and eventually became the modern English word 'airtight'.

Initially, it meant 'closely constrained to prevent air passage', and this meaning has largely remained the same in modern usage.