trailerPronunciation: /ˈtreɪlə/Translate trailer | into French | into German | into Italian | into Spanish Definition of trailer noun 1an unpowered vehicle towed by another, in particular: the rear section of an articulated lorry: forty lorry trailers loaded with fish an open cart: a farm trailer hauled by a tractor a platform for transporting a boat. North American a caravan. 2a series of extracts from a film or broadcast, used for advance publicity: terrific trailers for mediocre movies 3a thing that trails, especially a trailing plant. verb [with object] 1give advance publicity to (a film, broadcast, or proposal) by releasing extracts or selected details: the series has already been heavily trailered 2transport (something) by trailer: the aircraft is easy to trailer and will fit into any garagetrailer in other Oxford dictionaries Definition of trailer in the US English dictionary