Meathead
There are a few possibilities for this:
palooka
(Other definitions for dolt that I've seen before include "Simpleton" , "Dullard" , "dope" , "Dunce" , "Dimwit" .)
'meathead' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for palooka that I've seen before include "Bungler" , "Stupid oaf" , "clumsy type" .)