拳 (quán) means fist and is used in martial arts contexts (拳击, boxing; 太极拳, tai chi; 功夫, kungfu). It also appears in compounds related to fighting (出拳, to throw a punch; 挥拳, to swing a fist). Note: the source entry shows simplified 硂 which appears to be a data anomaly - the correct simplified character is 拳. 拳头 (quán tóu) means fist as a noun phrase. The measure word for punches is 拳 itself (打了一拳, threw one punch).