Hasten to make capital (6)
I believe the answer is:
athens
'capital' is the definition.
(capital of Greece)
'hasten to make' is the wordplay.
'to make' indicates anagramming the letters.
'hasten' is an anagram of 'ATHENS'.
(Other definitions for athens that I've seen before include "City of the Parthenon" , "Mediterranean capital" , "Plato's birthplace" , "Hasten to the Hellenic city" , "foreign city" .)