Tramp's house with bad smell (4)
I believe the answer is:
hobo
'tramp's' is the definition.
(both can mean a homeless person)
'house with bad smell' is the wordplay.
'house' becomes 'ho' (abbreviation for house).
'with' says to put letters next to each other.
'bad smell' becomes 'bo' (informal abbreviation for body odour).
'ho'+'bo'='HOBO'
(Other definitions for hobo that I've seen before include "Bum" , "Vagrant, tramp" , "Itinerant" , "Homeless American" , "Deer, situated at the back" .)