blab in WordNet English dictionary

1. divulge confidential information or secrets
   "Be careful--his secretary talks"
   spill the beans  let the cat out of the bag  talk  tattle  blab  peach  babble  sing  babble out  blab out 
   
2. speak (about unimportant matters) rapidly and incessantly
   chatter  piffle  palaver  prate  tittle-tattle  twaddle  clack  maunder  prattle  blab  gibber  tattle  blabber  gabble