Drink then swallows last to salve conscience
I believe the answer is:
superego
'salve conscience' is the definition.
'superego' can be an answer for 'conscience' (I've seen this before). I am not sure about the 'salve' bit.
'drink then swallows last' is the wordplay.
'drink' becomes 'sup' (I've seen this before).
'then swallows' becomes 'ere' (I can't explain this - if you can you should believe this answer much more).
'last' becomes 'go' ('go' can be a synonym of 'last').
'sup'+'ere'+'go'='SUPEREGO'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for superego that I've seen before include "Freudian concept of conscience" , "Moral part of the (Freudian) unconscious" , "Internal monitor of psyche" , "See group (anag.)" , "Part of the unconscious mind - pose urge (anag)" .)