Beaten and buried in back garden, naturally (6)
I believe the answer is:
tanned
'beaten' is the definition.
(to tan is to beat as a punishment)
'buried in back garden naturally' is the wordplay.
'back' is a reversal indicator.
'buried in' indicates the answer is hidden within the clue.
'dennat' can be found hidden inside 'garden naturally'.
'dennat' written backwards gives 'TANNED'.
'and' acts as a link.
(Other definitions for tanned that I've seen before include "Brown; severely beaten" , "Browned in the sun" , "Brown from sunbathing" , "Sunburned" , "With browned skin" .)