game face

[ geym feys ]
/ ˈgeɪm ˌfeɪs /

noun

a neutral or intense facial expression that suggests a focus on winning, as in a competitive sport or card game: The game faces at this poker tournament are as unflinching as stone.

Origin of game face

First recorded in 1950–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019