Caterer's vessel (3)
I believe the answer is:
urn
'caterer's vessel' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for urn that I've seen before include "Run to get large vase" , "Rounded vase" , "Vessel for tea or ashes" , "Keats wrote an ode on a Grecian one of these" , "Large pot for coffee or tea" .)