Ship's master roving out East (7)
I believe the answer is:
steamer
'ship's' is the definition.
(steamer is a kind of ship)
'master roving out east' is the wordplay.
'roving' indicates an anagram.
'out' is an insertion indicator.
'east' becomes 'e' ('E' can be a synonym of 'east').
'master' is an anagram of 'steamr'.
'steamr' enclosing 'e' is 'STEAMER'.
(Other definitions for steamer that I've seen before include "Old-style ship" , "One heats up" , "Old ship -- cooking utensil" , "Large vessel - cooking vessel" , "Vessel housing galley" .)