The stunted not-half ugly lout (4)
I believe the answer is:
thug
'lout' is the definition.
(I have seen 'Violent lout ' mean 'thug' so perhaps 'lout' could also mean 'thug')
'the stunted not-half ugly' is the wordplay.
'stunted' means to remove the last letter (the word is shorter than it usually is).
'not half' indicates taking half.
'the' with its last letter taken away is 'th'.
'ugly' halved is 'ug'.
'th'+'ug'='THUG'
(Other definitions for thug that I've seen before include "Heavy" , "Indian strangler - criminal" , "brute" , "Violent ruffian" , "Gorilla" .)