wap (n.)youdaoicibaDictYouDict[wap 词源字典]
"a hit, a blow," late 14c., probably of imitative origin. The verb (late 14c.) originally meant "to throw quickly or with violence," and in slang c. 1560-1730 it meant "to copulate." Related: Wapped; wapping.[wap etymology, wap origin, 英语词源]