Hit hard (informal) (5)
(Other definitions for clock that I've seen before include "Striker" , "Flashy black-market dealer" , "Notice" , "time" , "'Rock Around the --', 1956 film" .)
(Other definitions for wallop that I've seen before include "big hit" , "ale?" , "Strike very hard" , "Thrash - beer (slang)" , "Best" .)
(Other definitions for walloped that I've seen before include "affected by strikes?" , "Hit hard" .)