• mobile house; vehicle drawn by another vehicle; motion picture preview
• a trailer is a vehicle which is pulled by a car or van and which is used for transporting large or heavy items.
• a trailer is also the long rear section of an articulated lorry, in which the goods are carried.
• a trailer is also a long vehicle which people use as a home or office and which can be pulled behind a car; used in american english.
• a trailer for a film or television programme is a set of short extracts which are shown or broadcast to advertise it.
• motor vehicle equipped as traveling living quarters
• large truck used for transferring cargo