Changing tenure of the vessel (6)
I believe the answer is:
tureen
'the vessel' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'changing tenure' is the wordplay.
'changing' is an anagram indicator.
'tenure' anagrammed gives 'TUREEN'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for tureen that I've seen before include "basin" , "Large, deep serving dish with a cover" , "Holder of first course" , "wooden dish" , "A large deep soup dish" .)