babble vs gabble

babble and gabble both are nouns.

Word	Noun	Adjective	Verb	Adverb
babble	Yes	No	Yes	No
gabble	Yes	No	Yes	No

As verbs, gabble is a hypernym of babble; that is, gabble is a word with a broader meaning than babble:

babble (noun)	gabble (noun)
gibberish resembling the sounds of a baby	rapid and indistinct speech

babble (verb)	gabble (verb)
to talk foolishly	speak (about unimportant matters) rapidly and incessantly
divulge confidential information or secrets
utter meaningless sounds, like a baby, or utter in an incoherent way
flow in an irregular current with a bubbling noise