Sub.

tractor-trailer (Artjaazz); tumbrel; tumbril; wagon; wain; big rig truck (an 18-wheel truck • He was traveling at night north of Kenefick, and right behind a big rig truck when a fleeting movement from the side of the road caught his attention. (mysteriousuniverse.org) ART Vancouver)

Amerik.

trailer truck (Artjaazz); semi-trailer truck (wikipedia.org hellbourne)

Amerik., umg.

semi (от semi-trailer – седельный тягач с полуприцепом Artjaazz); semi-truck (Artjaazz); 18-wheeler (18-колесная Artjaazz); semi truck (In North America, the combination vehicles made up of a powered truck and one or more detachable trailers, are known as semi-tractor-trailers, tractor-trailers, semis, big rigs, semi trucks or eighteen-wheelers. 4uzhoj); big rig (a tractor-trailer combination 4uzhoj)

Autoind.

semitruck (Taras)

Autoind., Amerik.

rig (a tractor-trailer combination; осторожно, rig может означать и только сам тягач joyand)

Bauw.

wagon body

Brit.

articulated lorry (In the UK, the term "articulated lorry" refers to the combination of a tractor and a trailer. In the U.S., this is called a semi-trailer truck, "tractor-trailer" or "semi-truck" and would not necessarily be called articulated.