travelling salesman vs traveling salesman

travelling salesman and traveling salesman both are nouns.

Word	Noun	Adjective	Verb	Adverb
travelling salesman	Yes	No	No	No
traveling salesman	Yes	No	No	No

As nouns, travelling salesman and traveling salesman are synonyms defined as:

travelling salesman and traveling salesman: a salesman who travels to call on customers

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

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