open three-of-a-kind meld
In mahjong, a three-of-a-kind set completed by calling a discarded tile from another player. The set is displayed face-up. Contrast with 暗刻子 (アンコーツ), a concealed three-of-a-kind.
See also: 刻子
He called a green dragon tile and made an open three-of-a-kind meld.
Because an open three-of-a-kind includes a called tile, it tends to reveal your hand to other players.
From Chinese 明刻子 (míng kè zi), literally 'open carved/engraved child', a mahjong term for an exposed triplet. The reading ミンコーツ reflects the Chinese pronunciation adapted into Japanese mahjong terminology.