Son getting punched, not hard, is floored (7)
I believe the answer is:
stumped
'is floored' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for stumped that I've seen before include "Out on the field" , "Bewildered (on the way out?)" , "Dismissed" , "Defeated by puzzle" , "Baffled" .)