Hillbilly's endless criticism following game (6)
I believe the answer is:
rustic
'hillbilly's' is the definition.
(thesaurus)
'endless criticism following game' is the wordplay.
'endless' means to remove the last letter.
'criticism' becomes 'stick' (as in giving someone stick).
'following' means one lot of letters go next to another.
'game' becomes 'RU' (rugby union).
'stick' with its final letter removed is 'stic'.
'stic' after 'ru' is 'RUSTIC'.
(Other definitions for rustic that I've seen before include "Simple and unsophisticated as in the country" , "Peasant; roughly made" , "Hodge" , "Charmingly simple" , "country cousin" .)