noun
two pawns on the same file; illegal double pawn drop
Shogi term for the illegal move of dropping a second unpromoted pawn onto a file that already contains one of the player's unpromoted pawns.
二歩は反則負けになる。
Making a double pawn drop results in a loss by foul.
初心者はうっかり二歩を打ってしまうことがある。
Beginners sometimes accidentally make an illegal double pawn drop.