Condition of prison (4)
I believe the answer is:
nick
I believe this is a double definition.
'condition' is the first definition.
(as in the phrase 'in good nick')
'prison' is the second definition.
(slang)
'of' is the link.
(Other definitions for nick that I've seen before include "Score - police station" , "Cut; steal (colloq.)" , "Prison - cut" , "Notch; steal" , "Arrest - steal" .)