kanchan wait; closed wait
In mahjong, a wait for the middle tile of a sequence (e.g., holding 4-6 and waiting for 5).
from Chinese
See also: 嵌張待ち (カンチャンまち)
A kanchan wait is hard to win with because there is only one type of tile you can win on.
wait for the middle tile of a run to complete a hand
From Chinese mahjong terminology; the exact derivation is uncertain.