blabber

nouns

one who reveals confidential information in return for money
betrayer, blabber, informer, rat, squealer
is derived from
blab

verbs

speak (about unimportant matters) rapidly and incessantly
blab, blabber, chatter, clack, gabble, gibber, maunder, palaver, piffle, prate, prattle, tattle, tittle-tattle, twaddle