gumming vs chewing

gumming and chewing both are nouns.

Word	Noun	Adjective	Verb	Adverb
gumming	Yes	No	No	No
chewing	Yes	No	No	No

As nouns, chewing is a hypernym of gumming; that is, chewing is a word with a broader meaning than gumming:

gumming: ineffectual chewing (as if without teeth)
chewing: biting and grinding food in your mouth so it becomes soft enough to swallow

Other hypernyms of gumming include chew, manduction, mastication.

gumming (noun)	chewing (noun)
ineffectual chewing (as if without teeth)	biting and grinding food in your mouth so it becomes soft enough to swallow