Initially walloping that man for every snivel (7)
I believe the answer is:
whimper
'snivel' is the definition.
(I've seen this before)
'initially walloping that man for every' is the wordplay.
'initially' indicates taking the first letters.
'that man' becomes 'him' (him refers to a man).
'for every' becomes 'per' ('per' means 'for each' or 'for every').
The initial letter of 'walloping' is 'w'.
'w'+'him'+'per'='WHIMPER'
(Other definitions for whimper that I've seen before include "Whine" , "Complaint" , "Sob" , "Cry feebly or plaintively" , "Snivel" .)