We're breaking out of jug! (4)
I believe the answer is:
ewer
'jug' is the definition.
(type of vessel)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ewer that I've seen before include "Container" , "Water-jar" , "Decorative pitcher" , "Sort of jug" , "water-carrier" .)