tell tales out of school

Verb

tell tales out of school (third-person singular simple present tells tales out of school, present participle telling tales out of school, simple past and past participle told tales out of school)

1. (idiomatic) To reveal confidential or sensitive information; to gossip.
   • I see then we have both been at school. But did you never, when you were there, hear it said, "Tell no tales out of school?"1831 April 27, “Court of Aldermen”, in The Times, page 4
   • Mr. Washington had seen the gentlemen of honour and fashion over their cups, and perhaps thought that all their sayings and doings were not precisely such as would tend to instruct or edify a young man on his entrance into life; but he wisely chose to tell no tales out of school.1857, William Makepeace Thackeray, chapter 8, in The Virginians

   Synonyms:

   blab, gossip, squeal, talk out of turn