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”).
Meanings
(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:
(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:
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”).
Meanings
(ambitransitive) To tell tales; to gossip without reserve or discretion.
blab about something
And yonder a vile physician blabbing / The case of his patient. 1855, Alfred Tennyson, “(please specify the page)”, in Maud, and Other Poems, London: Edward Moxon, […], →OCLC:
1998, "Helga Blabs It All", TV episode in season 3 of Hey Arnold!, animated television series created by Craig Bartlett
Helga Blabs It All.