Discharge of gas put through drink (5)
I believe the answer is:
rheum
'discharge' is the definition.
(I've seen this before)
'gas put through drink' is the wordplay.
'gas' becomes 'He' (chemical symbol for Helium).
'put through' becomes 'rum' (I am not sure about this - if you are sure you should believe this answer much more).
'drink' indicates putting letters inside.
'he' placed within 'rum' is 'RHEUM'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for rheum that I've seen before include "Moist discharge from nose or eyes" , "Catarrh" , "sign of illness" , "Eyes watering" , "nasal discharge" .)