To knock or strike; commonly used in terms for knocking on a door.

To kowtow or touch one's head to the ground as a sign of respect; often a shortened form of 叩头 kòu​tóu or 叩首 kòu​shǒu

(literary) To ask or inquire; specifically to seek information from someone of higher status.

(archaic) To hold, pull, or restrain; used in the same sense as 扣 kòu.

a Chinese surname