concealed pung; concealed three-of-a-kind
In mahjong, a set of three identical tiles drawn entirely from the wall without claiming any discards; the set is kept hidden from other players.
from Chinese àn kè zi
See also: 刻子
When you form a concealed pung, place it face down in front of you.
In this hand, I was able to make two concealed pungs.
From Chinese 暗刻子 (àn kè zi), a mahjong term meaning 'concealed pung'. The reading アンコーツ reflects the Chinese pronunciation adapted into Japanese mahjong terminology.