confab vs chew the fat

confab is a noun but chew the fat is not a noun.

Word	Noun	Adjective	Verb	Adverb
confab	Yes	No	Yes	No
chew the fat	No	No	Yes	No

As verbs, confab and chew the fat are synonyms defined as:

confab and chew the fat: talk socially without exchanging too much information

confab (noun)	chew the fat (noun)
an informal conversation

confab (verb)	chew the fat (verb)
talk socially without exchanging too much information	talk socially without exchanging too much information
have a conference in order to talk something over