叩 (w)

(kòu) to knock; to kowtow

叩应 (w)

(kòuyìng) call-in (loanword)

叩拜 (w)

(kòubài) to bow in salute; to kowtow

叩球 (w)

(kòuqiú) spike (volleyball)

叩见 (w)

(kòujiàn) to kowtow in salute

叩谒 (w)

(kòuyè) to visit (esp. one's superiors)

叩门 (w)

(kòumén) to knock on a door

叩关 (w)

(kòuguān) to knock at the gate (old); to make an approach; to invade; to attack the goal (sports)

叩头 (w)

(kòutóu) to kowtow (traditional greeting, esp. to a superior, involving kneeling and pressing one's forehead to the ground); also written 磕頭|磕头[ke1 tou2]

叩首 (w)

(kòushǒu) to kowtow; also written 磕頭|磕头[ke1 tou2]