An impassive facial expression cultivated to prevent other players from determining whether one's actions in the game are the result of a quality hand, or of bluffing
Though he thought he had a perfect poker face, he had a number of tells his opponents soon learned.
A poker face is an expression on your face that shows none of your feelings. In business a poker face can be very useful She managed to keep a poker face
If you are poker-faced, you have a calm expression on your face which shows none of your thoughts or feelings. His expressions varied from poker-faced to blank The officer listened, poker-faced. showing no expression on your face