Question: what is the idiomatic expression of brave?
Answer: Put on a brave front (अपने आप को साहसी दिखाना): To appear or make oneself seem more courageous, resolute, or dauntless than one really feels. E. g. I could feel my knees shaking with terror before my commencement speech, but I put on a brave front and stepped out onto the stage to deliver it.