Hard-up eccentric in seclusion (6)
I believe the answer is:
purdah
'seclusion' is the definition.
(I've seen this before)
'hard-up eccentric' is the wordplay.
'eccentric' is an anagram indicator.
'hard'+'up'='hardup'
'hardup' anagrammed gives 'PURDAH'.
'in' acts as a link.
(Other definitions for purdah that I've seen before include "Period of seclusion" , "Hindu system of keeping women from sight of men" , "Muslim practice of keeping women from sight of men or strangers" , "Muslim and Hindu custom of keeping women secluded" , "Screen - custom of keeping women in seclusion" .)