Wiktionary
alt. (context idiomatic English) 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. vb. (context idiomatic English) 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.
Usage examples of "talk out of turn".
But Burzoe had been Godarz's right hand for many years, something she couldn't have done without holding secrets close, and Roshnani did not seem one to talk out of turn.
Cyder was already connected with Vertue in some way via the energy crystal, so she wouldn't talk out of turn.
Take a soldier at war: if he's allowed the freedom to talk out of turn, he may give his unit away and they'll be killed.