Naive drunk touring northern capital (6)
I believe the answer is:
vienna
'capital' is the definition.
(capital of Austria)
'naive drunk touring northern' is the wordplay.
'drunk' indicates anagramming the letters.
'touring' is an insertion indicator (tour can mean to go around).
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'naive' is an anagram of 'viena'.
'viena' going around 'n' is 'VIENNA'.
(Other definitions for vienna that I've seen before include "Capital on the Danube Canal" , "sort of sausage" , "Wien" , "Strauss 'Tales from the . . . . . . Woods'" , "somewhere in Austria" .)