three concealed pungs
A mahjong hand containing three concealed triplets (pungs). One of the standard yaku, worth two han. The hand must be won by drawing the winning tile; if the winning tile completes a pair, the yaku is still valid, but if it completes a pung, the pung is considered open and the yaku is lost.
from Chinese sān àn kè
See also: 暗刻 (アンコー)
Three concealed pungs is a yaku that only counts if you draw the winning tile with a closed hand.
This hand is a mangan with three concealed pungs and two dora.
From Chinese 三暗刻 (sān àn kè), literally 'three concealed carvings'. The term is used in Japanese mahjong with the same meaning.