Northern beer knocked back in style (4)
I believe the answer is:
elan
'style' is the definition.
(synonyms)
'northern beer knocked back' is the wordplay.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'beer' becomes 'ale' (type of beer).
'knocked back' shows that the letters should be reversed in order.
'n'+'ale'='nale'
'nale' back-to-front is 'ELAN'.
'in' acts as a link.
(Other definitions for elan that I've seen before include "Dash in France" , "spirit" , "Energetic style - anagram of 3" , "Impressive and energetic style" , "Vitality" .)