confab vs talk over

confab is a noun but talk over is not a noun.

Word	Noun	Adjective	Verb	Adverb
confab	Yes	No	Yes	No
talk over	No	No	Yes	No

As verbs, talk over is a hypernym of confab; that is, talk over is a word with a broader meaning than confab:

confab: have a conference in order to talk something over
talk over: speak with others about (something); talk (something) over in detail; have a discussion

Other hypernyms of confab include discuss, hash out.

confab (noun)	talk over (noun)
an informal conversation

confab (verb)	talk over (verb)
talk socially without exchanging too much information	speak with others about (something); talk (something) over in detail; have a discussion
have a conference in order to talk something over