The Collaborative International Dictionary of English v.0.48:
Trailer \Trail"er\, n.
1. a wheeled vehicle without a motor, designed to be drawn by
a motor vehicle in front of it; specifically:
(a) such a vehicle used on street railroads. Called also
(b) the large wheeled wagon or van pulled by a tractor in
a tractor-trailer combination.
(c) a vehicle equipped as a mobile dwelling unit, pulled
by an automobile or other mtor vehicle, and used as a
dwelling when parked; -- also called a mobile home.
(d) A wheeled motorless open wagon designed to carry a
heavy object, such as a boat trailer.
2. (Movies) A short blank segment of movie film attached to
the end; -- used for convenient insertion of the film in a
3. (Movies) A short film consisting primarily of one or more
short portions of a film, used in promotions or
advertisements shortly before initial release of a film.
4. A part of an object which extends some distance beyond the
main body of the object; as, the trailer of a plant.
trailer park. An area equipped to accommodate trailers,
often with outlets supplying electrical power and water.
Called also trailer camp, trailer court.