| a combination trucking unit consisting of a tractor hooked up to a full trailer or a semitrailer. Also called semitrailer, semitruck. Compare rig 1 (def. 10). |
| trac·tor-trail·er (trāk'tər-trā'lər) n. A truck consisting of a tractor attached to a semitrailer or trailer, used for transporting loads. |