wallop wallop /ˈwɑːləp/

noun

1. [Informal] A severe blow  ( wallop [Informal] )
   a severe blow
   
2. [Informal] A forceful consequence; a strong effect  ( wallop [Informal] , impact )
   a forceful consequence; a strong effect
    The book had an important impact on my thinking
   the book had an important impact on my thinking
    The book packs a wallop
   the book packs a wallop
   

verb

1. () [Informal] Defeat soundly and utterly  ( wallop [Informal] )
   defeat soundly and utterly
    We'll wallop them!
   We'll wallop them!
   
2. () [Informal] Hit hard  ( bash [Informal] , bonk [Informal] , bop [Informal] , belt , sock [Informal] , wham [Informal] , whap [Informal, N. American] , whop [Informal] , boink [Informal, N. American] , wallop [Informal] , whack [Informal] )
   hit hard
    The teacher whacked the boy
   The teacher whacked the boy