trucking rig vs semi

trucking rig and semi both are nouns.

Word	Noun	Adjective	Verb	Adverb
trucking rig	Yes	No	No	No
semi	Yes	No	No	No

As nouns, trucking rig and semi are synonyms defined as:

trucking rig and semi: a truck consisting of a tractor and trailer together

Other synonyms of trucking rig include articulated lorry, rig, tractor trailer, trailer truck.

trucking rig (noun)	semi (noun)
a truck consisting of a tractor and trailer together	a trailer having wheels only in the rear; the front is supported by the towing vehicle
	a truck consisting of a tractor and trailer together
	one of the two competitions in the next to the last round of an elimination tournament