Consequently most of the beer is not drunk (5)
I believe the answer is:
sober
'is not drunk' is the definition.
(I've seen this before)
'consequently most of the beer' is the wordplay.
'consequently' becomes 'so' (synonyms).
'most of the beer' becomes 'ber' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'so'+'ber'='SOBER'
Can you help me to learn more?
(Other definitions for sober that I've seen before include "Serious, restrained" , "On the wagon" , "Unaffected by drink" , "Abstinent" , "Sensible - clear-headed" .)