noun
menko; card-flipping game
A traditional Japanese children's game played with thick circular or rectangular cards. Players slap their card onto the ground to flip over an opponent's card.
昔、よく友達とメンコをして遊んだ。
I used to play menko with my friends a lot when I was young.
このメンコは厚くて、なかなかひっくり返らない。
This menko card is thick and hard to flip over.
The origin of the word is uncertain. It may be related to the onomatopoeic sound of slapping, but the exact derivation is unclear.