Water pitcher (4)
I believe the answer is:
'water pitcher' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ewer that I've seen before include "Open vessel with handle and spout" , "Pitcher, water jug" , "A wide-mouthed water-jug" , "Large water jug" , "Were (anag)" .)