Possibly violated a joint (8)
I believe the answer is:
dovetail
'a joint' is the definition.
(I know that dovetail is a type of mortise and tenon)
'possibly violated' is the wordplay.
'possibly' is an anagram indicator.
'violated' with letters rearranged gives 'DOVETAIL'.
(Other definitions for dovetail that I've seen before include "Joint with fan-shaped tenon" , "good joint" , "Violated (anag) -- mortise joint" , "Fit snugly" , "Joint of tenon and mortise" .)