Some finer vases for the emperor (5)
I believe the answer is:
nerva
'emperor' is the definition.
(I know this)
'some finer vases for' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'NERVA' is hidden within 'finer vases for'.
'the' is the link.
(Other definitions for nerva that I've seen before include "Short-lived emperor" , "Roman emperor, ninety six to ninety eight" .)