If someone blabs about something secret, they tell people about it. Her mistake was to blab about their affair No blabbing to your mates! She'll blab it all over the school. to tell someone something that should be kept secret blab to (blab (14-20 centuries), probably from the sound)
blabs
Pronunciation
Etymology
[ 'blab ] (noun.) 14th century. Middle English blabbe; akin to Middle English blaberen.