blab

verb

Reveal secrets by indiscreet talk.

noun

A person who blabs.

SYNONYMS

betrayblow something wide openblow the gaffblurt outcoughdisclosedivulgegive awaygive the game/show awayleaklet onlet outlet sliplet the cat out of the bagopen one's mouthrevealspillspill the beanstake/blow the lid offtalktell