The Vietnamese word "biện bác" is a verb that means "to reason" or "to argue." It refers to the ability to think critically and present logical arguments in discussions or debates. When someone is described as "người có tài biện bác," it means they are a person who has a talent for arguing effectively.
Although "biện bác" primarily refers to reasoning and arguing, in different contexts, it can also imply a deeper level of critical thinking and analysis.