The Vietnamese phrase "nói thánh tướng" can be translated to English as "to speak braggingly" or "to rant." It's often used to describe someone who talks in an exaggerated or boastful manner, making grand claims or speaking in a way that is not entirely truthful or realistic.
In summary, "nói thánh tướng" is a phrase used to describe the act of speaking in a boastful or exaggerated way. It is often used in casual conversation and can have a negative connotation.