blab
blab
verb
To carelessly reveal secrets or private information, often without thinking.
"Don't blab about our surprise party!"
Thesaurus
Synonyms: tattle, gabble, prate, gibber, maunder, clack, tittle-tattle, palaver, blabber, twaddle, prattle, piffle
Antonyms: keep one's mouth shut, keep quiet, shut one's mouth