From Longman Dictionary of Contemporary EnglishAirstreamAir‧stream /ˈeəˌstriːm $ ˈeər-/ trademark noun [countable] a type of silver-coloured trailer (=a vehicle which contains beds, a kitchen etc and which is pulled by a car), similar to a bullet in shape. They were first made in the US in the 1930s and continue to be popular and fashionable.