A joint badly violated (8)
I believe the answer is:
dovetail
'a joint' is the definition.
(I know that dovetail is a type of mortise and tenon)
'badly violated' is the wordplay.
'badly' is an anagram indicator.
'violated' with letters rearranged gives 'DOVETAIL'.
(Other definitions for dovetail that I've seen before include "Come together" , "Wood joint" , "Joint - fit neatly" , "Woodworking joint" , "Fit together well" .)