verb
to utter or speak rapidly, inarticulately, and usually unintelligibly
a gibbering idiot
Synonyms: babble, chatter, gabble, jabber
Related Word: blather, drivel, prate, prattle, yammer; stammer, stutter; mumble, mutter; mow
Idioms: run off at the mouth
Contrasted words: articulate, enunciate, pronounce