Horribly hard up in seclusion (6)
I believe the answer is:
purdah
'seclusion' is the definition.
(I've seen this before)
'horribly hard up' is the wordplay.
'horribly' indicates anagramming the letters.
'hard'+'up'='hardup'
'hardup' anagrammed gives 'PURDAH'.
'in' acts as a link.
(Other definitions for purdah that I've seen before include "System in Muslim communities of keeping women from the sight of men" , "Seclusion of women as religious practice" , "Muslim practice of keeping women from sight of men or strangers" , "Hindu system of keeping women from sight of men" , "Muslim and Hindu custom of keeping women secluded" .)