To make a remark or provide information when it is inappropriate or indiscreet to do so, or when one does not have permission or the authority to do so.
Often said of children: to report incriminating information about another person, or a person's wrongdoing; to tell on somebody.
To chatter; to gossip.
A tattletale.
Often said of children: a piece of incriminating information or an account of wrongdoing that is said about another person.
Idle talk; gossip; (countable) an instance of such talk or gossip.