blab

Etymology

From Middle English blabben (“to talk foolishly”), perhaps from Middle English blabbe (“idle talk; talebearer”). Compare Middle English blaberen (“to blabber, babble”), Middle High German blabezen (“to stammer, babble”).

verb

1. (transitive, intransitive) To tell tales; to gossip without reserve or discretion.
   1998, "Helga Blabs It All", TV episode in season 3 of Hey Arnold!, animated television series created by Craig Bartlett Helga Blabs It All.
2. to speak carelessly or excessively

noun

1. (countable) One who blabs; a babbler; a telltale; a gossip or gossiper.
   "You'd better have shoved your grey snout in a hornets' nest, Badger, than suggest that I am the blab," said Nikabrik. 1951, C. S. Lewis, Prince Caspian: The Return to Narnia
2. (uncountable) Gossip; prattle.
   Audie never liked him because he was further in with old Craig than he was, bragging and blowing about his work and the things he could do, while Audie sat quiet as a mouse listening to his blab. 1976, David Toulmin, Blown Seed, page 148