babble vs piffle

babble and piffle both are nouns.

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

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

babble (noun)	piffle (noun)
gibberish resembling the sounds of a baby	trivial nonsense

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