Vessel always seen out West (4)
I believe the answer is:
ewer
'vessel' is the definition.
(ewer is a kind of vessel)
'always seen out west' is the wordplay.
'always seen' becomes 'eer' (I can't explain this - if you can you should give a lot more credence to this answer).
'out' means one lot of letters goes inside another.
'west' becomes 'W' (synonyms).
'eer' enclosing 'w' is 'EWER'.
Can you help me to learn more?
(Other definitions for ewer that I've seen before include "Decorative pitcher" , "Jug with wide spout" , "Container" , "Large water-jug" , "Large water jug" .)