Tramp who borrows houses (4)
I believe the answer is:
hobo
'tramp' is the definition.
(synonyms)
'who borrows houses' is the wordplay.
'houses' says the answer is hidden in the clue (part of the clue houses the answer).
'HOBO' is hidden within 'who borrows'.
(Other definitions for hobo that I've seen before include "Deer, situated at the back" , "Bum" , "Homeless American" , "Vagrant, tramp" , "Vagrant (US)" .)