Arrogant drunk quaffing a Spanish port (9)
I believe the answer is:
tarragona
'spanish port' is the definition.
(I've seen this before)
'arrogant drunk quaffing a' is the wordplay.
'drunk' indicates anagramming the letters.
'quaffing' means one lot of letters goes inside another (to quaff is to drink or consume).
'arrogant' with letters rearranged gives 'tarrgona'.
'tarrgona' enclosing 'a' is 'TARRAGONA'.
(Other definitions for tarragona that I've seen before include "port, in Spain" , "Spanish city" , "Spanish port" , "Spanish wine" , "Spanish province" .)