a box on wheels that is pulled by a car and is used for taking things from one place to another:
The car was pulling a trailer with a motorcycle on it.
the separate back part of a large truck
a wheeled vehicle for living or travelling in, especially for holidays, that contains beds and cooking equipment and can be pulled by a car
an advertisement for a film or a television or radio programme, consisting of short parts taken from it:
I saw a trailer for the new series of "Game of Thrones" last night.
a vehicle without an engine, often in the form of a flat frame or a container, that can be pulled by another vehicle
A trailer is also a house on wheels that can be moved by pulling it:
We bought a trailer for camping trips.
A trailer is also a mobile home
an advertisement for a movie, often showing a few, brief parts of it
an advertisement for a film, or television or radio programme, consisting of short parts taken from it:
You can watch a trailer for the new series online.
Hollywood has been circulating movie trailers on the Web for years.
the separate back part of a large truck used for carrying goods:
It isn't cost-effectitve to have trucks carrying half-empty trailers for part of their journey.
a box on wheels that is pulled by a car and is used for taking things from one place to another