Clubber gazed around, taking in Croatian capital (6)
I believe the answer is:
zagreb
'croatian capital' is the definition.
(capital of Croatia)
'clubber gazed around taking in' is the wordplay.
'taking in' says the answer is hidden in the clue (the answer has been taken into the clue).
'around' says the letters should be written in reverse.
'bergaz' is hidden within 'clubber gazed'.
'bergaz' written backwards gives 'ZAGREB'.
(Other definitions for zagreb that I've seen before include "European capital" , "Croatia's capital city" , "Croatian city" , "European city" , "on River Sava" .)