traveling salesman vs travelling salesman

traveling salesman and travelling salesman both are nouns.

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

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

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

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

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