Wretched person without room (4)
I believe the answer is:
worm
'wretched person' is the definition.
(I've seen this before)
'without room' is the wordplay.
'without' becomes 'wo' (abbreviation of 'without', normally with a slash).
'room' becomes 'rm' (abbreviation for room).
'wo'+'rm'='WORM'
(Other definitions for worm that I've seen before include "Insect larva" , "Wretched person" , "Creeping invertebrate" , "Annelid" , "Slither" .)