After period of time, man is giving punishment (8)
I believe the answer is:
spanking
'punishment' is the definition.
(spanking is a kind of punishment)
'after period of time man is' is the wordplay.
'after' is a charade indicator (letters next to each other).
'period of time' becomes 'span' (span is a kind of period of time).
'man is' becomes 'king' (I can't explain this - if you can you should believe this answer much more).
'span' put next to 'king' is 'SPANKING'.
'giving' acts as a link.
Can you help me to learn more?
(Other definitions for spanking that I've seen before include "procedure for maintaining discipline!" , "Hiding" , "Very large" , "Quick and energetic (1)" , "Fantastic" .)