Discharge from space, we hear? (5)
I believe the answer is:
rheum
'discharge' is the definition.
(thesaurus)
'space we hear?' is the wordplay.
'space' becomes 'room' (room is a kind of space).
'we hear?' shows a homophone (sound like).
'room' is a homophone of 'RHEUM'.
'from' is the link.
(Other definitions for rheum that I've seen before include "sign of illness" , "Watery stuff" , "Watery fluid" , "Discharge of water" , "Eyes watering" .)