trailer

Concise Oxford English Dictionary © 2008 Oxford University Press:
trailer/ˈtreɪlə(r)/

▶noun

• 1 an unpowered vehicle towed by another.

  ■ the rear section of an articulated truck.

  ■ N. Amer. a caravan.

• 2 an extract from a film or programme used for advance advertising.

• 3 a trailing plant.

▶verb

• 1 advertise with a trailer.

• 2 transport by trailer.