Neighbour of judge in trouble at home (6)
I believe the answer is:
'neighbour' is the definition.
(I've seen this before)
'judge in trouble at home' is the wordplay.
'judge' becomes 'j' (abbreviation for judge).
'in' is an insertion indicator.
'trouble' becomes 'ado' (I've seen this before).
'at home' becomes 'in' (similar in meaning).
'j' put into 'ado' is 'adjo'.
'of' is the link.
(Other definitions for adjoin that I've seen before include "Interconnect", "Be nineteen [NEXT]", "Neighbour", "Lie next to", "Butt up against".)