Drained state of pint seems to require refreshing (9)
I believe the answer is:
emptiness
'drained state' is the definition.
'emptiness' can be an answer for 'state' (emptiness is a kind of state). I'm not sure about the 'drained' bit.
'pint seems to require refreshing' is the wordplay.
'pint seems' can be anagrammed to 'EMPTINESS'.
But, I'm not sure how this is indicated.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for emptiness that I've seen before include "Vacancy, void" , "Vacuity" , "Void state" , "Lack of substance" , "Lack of content" .)