chasing riichi; riichi called after another player's riichi
In mahjong, a riichi declaration made immediately after another player has declared riichi, often as a defensive or pressuring move. The term is specific to the game and not used outside mahjong contexts.
See also: リーチ
I declared chasing riichi right after my opponent called riichi.
追っかけリーチはリスクが高いが、一発逆転を狙える。
Chasing riichi is risky, but you can aim for a comeback.
Compound of 追っかけ (chasing) and リーチ (riichi, from English 'reach'). The term is a mahjong-specific coinage.