Synonyms for Blabber (same or very similar meaning)
WordNet sense 1 (one who reveals confidential information in return for money):
betrayer, informer, rat, squealer
WordNet sense 2 (speak (about unimportant matters) rapidly and incessantly):
blab, chatter, clack, gabble, gibber, maunder, palaver, piffle, prate, prattle, tattle, tittle-tattle, twaddle
From the ODE community, based on WordNet
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