1. to demand that someone prove a claim; to challenge in order to expose an empty pretense or threat

1. They're bragging they can beat us badly. C’mon. Let’s call their bluff.

2. I called his bluff just to see if he really meant what he said.

3. I told my parents that I had gotten passing grades in all my classes, but they didn’t believe me. They called my bluff and asked to see my report card.

4. The bank robber threatened to shoot the bank guard, but the guard called the robber’s bluff by walking up to him and taking away his gun.

5. You don't believe me? Call my bluff. See what happens.