Caterer's dispenser (6)
'caterer's dispenser' 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 "Tall vase with stem" , "Spore-producing capsule of a moss" , "Holder of the Ashes?" , "Large pot for coffee or tea" , "Repository for ashes" .)