Seclusion of hard-up criminal (6)
I believe the answer is:
purdah
'seclusion' is the definition.
(I've seen this before)
'hard-up criminal' is the wordplay.
'criminal' indicates anagramming the letters.
'hard'+'up'='hardup'
'hardup' anagrammed gives 'PURDAH'.
'of' acts as a link.
(Other definitions for purdah that I've seen before include "Muslim and Hindu custom of keeping women secluded" , "State of social isolation" , "Screening curtain; seclusion" , "Muslim practice of keeping women from sight of men or strangers" , "Eastern tradition of keeping women secluded" .)