noun
two-pair wait; waiting to pung either of two pairs
Mahjong term: a tenpai hand with two pairs, waiting to complete either into a pung (triplet) to win.
シャンポン待ちでリーチをかけた。
I declared riichi with a two-pair wait.
シャンポン待ちは、どちらの対子を刻子にしても和了れる形だ。
A two-pair wait is a shape where you can win by turning either pair into a triplet.
From Chinese 双碰 (shuāng pèng, 'double pung'), borrowed into Japanese mahjong terminology as シャンポン.