Shelter to put up for poor person (4-3)
I believe the answer is:
have-not
'poor person' is the definition.
('have-not' can be a synonym of 'poor person')
'shelter to put up' is the subsidiary indication.
'shelter' becomes 'haven' (haven is a kind of shelter).
'put up' shows that the letters should be reversed in order.
'to' back-to-front is 'ot'.
'haven'+'ot'='havenot'
'for' is the link.
(Other definitions for have-not that I've seen before include "Economically disadvantaged person" , "Someone with meagre possessions" , "Person of little material wealth" , "Deprived person" , "Someone who lacks possessions" .)