tap out
phrasal verb with tap verb uk/tæp/ us/tæp/ -pp-
（武术运动中）拍击地面以示认输
in mixed martial arts and similar sports, to tap the floor to show that you accept that your competitor has beaten you
Suddenly he dropped to his knees and tapped out. 他忽然跪倒在地，拍击地面表示认输。