Nouns

(n)tattle, singing, tellingdisclosing information or giving evidence about another

Verbs

(v)chatter, piffle, palaver, prate, tittle-tattle, twaddle, clack, maunder, prattle, blab, gibber, tattle, blabber, gabblespeak (about unimportant matters) rapidly and incessantly
(v)spill the beans, let the cat out of the bag, talk, tattle, blab, peach, babble, sing, babble out, blab outdivulge confidential information or secrets“Be careful — his secretary talks”