The ships possibly left to go out East (5)
I believe the answer is:
fleet
'the ships' is the definition.
(I've seen this before)
'left to go out east' is the wordplay.
'to go' indicates an anagram (I've seen 'went' mean this ('go' can mean move)).
'out' indicates putting letters inside.
'east' becomes 'e' (synonyms).
'left' with letters rearranged gives 'flet'.
'flet' enclosing 'e' is 'FLEET'.
'possibly' is the link.
(Other definitions for fleet that I've seen before include "Swift like naval force" , "Navy - quick" , "group of taxis, for example" , "Street of the hack" , "Naval force or collection of buses" .)