Tyrant, son punching revolutionary was a drunkard (6)
I believe the answer is:
despot
'tyrant' is the definition.
(I know that tyrant can be written as despot)
'son punching revolutionary was a drunkard' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'punching' indicates putting letters inside (inserted letters punch or puncture others).
'revolutionary' says the letters should be written in reverse (letters revolve around).
'was a drunkard' becomes 'toped' (tope can mean to drink to excess).
'toped' back-to-front is 'depot'.
's' placed inside 'depot' is 'DESPOT'.
(Other definitions for despot that I've seen before include "Arbitrary ruler" , "Gaddafi, say" , "who treats others badly?" , "Person with more than enough power" , "monster?" .)