We're told chamber, say, is for discharge? (5)
I believe the answer is:
rheum
'is for discharge?' is the definition.
(I've seen this before)
'we're told chamber' is the wordplay.
'we're told' shows a homophone (sound like).
'chamber' becomes 'room' (I've seen this in another clue).
'room' sounds like 'RHEUM'.
'say' acts as a link.
(Other definitions for rheum that I've seen before include "Poetic tears" , "Catarrh" , "runny nose" , "drips from the nose" , "Rhubarb genus; a head cold" .)