air-bag

The word 'airbag' is a transparent modern compound, directly combining two Old English roots to describe its function. 'Air', tracing back to Greek 'aēr' meaning the atmosphere or breathable gas, specifies the inflating medium. 'Bag', of Old Norse origin meaning a sack or pouch, describes the physical container that deploys. The term logically and literally denotes a "bag of air," created in the mid-20th century to name an automotive safety device designed to cushion occupants by rapidly inflating a nylon fabric pouch with gas upon impact.

Structure: air (gas) + bag (container) - air: From Middle English 'air', from Old French 'air', from Latin 'āēr', from Ancient Greek 'ἀήρ' (aḗr, "air, mist, haze"). In this compound, it denotes the gaseous substance that inflates the device. - bag: From Middle English 'bagge', from Old Norse 'baggi' ("bag, pack, bundle"). In this compound, it denotes a flexible container or sack.