travelling salesman vs commercial traveller

travelling salesman and commercial traveller both are nouns.

Word	Noun	Adjective	Verb	Adverb
travelling salesman	Yes	No	No	No
commercial traveller	Yes	No	No	No

As nouns, travelling salesman and commercial traveller are synonyms defined as:

travelling salesman and commercial traveller: a salesman who travels to call on customers

Other synonyms of travelling salesman include bagman, commercial traveler, roadman, traveling salesman.

travelling salesman (noun)	commercial traveller (noun)
a salesman who travels to call on customers	a salesman who travels to call on customers