Trailer - (n.) One who, or that which, trails.

Trailer - (n.) A part of an object which extends some distance beyond the main body of the object; as, the trailer of a plant.

Trailer - n. 1 set of brief extracts from a film etc., used to advertise it in advance. 2 vehicle towed by another, esp.: a the rear section of an articulated lorry. B an open cart. C a platform for transporting a boat etc. D us a caravan.