Caught with joint in nick (4)
I believe the answer is:
chip
'nick' is the definition.
('chip' can be a synonym of 'nick')
'caught with joint' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'with' is a charade indicator (letters next to each other).
'joint' becomes 'hip' (hip is a kind of joint**).
'c'+'hip'='CHIP'
'in' is the link.
(Other definitions for chip that I've seen before include "Off the old block, he's junior" , "Shaving (found on one's shoulder?)" , "Small fragment, off the old block possibly" , "loft" , "Murphy sliced" .)