Chief official of Venice or Genoa (4)
I believe the answer is:
doge
'chief official of venice or genoa' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for doge that I've seen before include "Old chief magistrate in Venice and Genoa" , "Former title of the chief magistrate in Venice" , "Old Italian chief magistrate" , "Magistrate of 14 (historical)" , "foreign magistrate" .)