Nouns

(n)gibberish, gibberunintelligible talking

Verbs

(v)chatter, piffle, palaver, prate, tittle-tattle, twaddle, clack, maunder, prattle, blab, gibber, tattle, blabber, gabblespeak (about unimportant matters) rapidly and incessantly
(v)gibberchatter inarticulately; of monkeys