Sail around Eastern passage (5)
I believe the answer is:
aisle
'passage' is the definition.
(aisle can mean a path or passageway)
'sail around eastern' is the wordplay.
'around' is an anagram indicator.
'eastern' becomes 'e'.
'sail' is an anagram of 'aisl'.
'aisl'+'e'='AISLE'
(Other definitions for aisle that I've seen before include "Way between seats" , "Passageway between blocks of seats" , "Passages between seating areas" , "Walkway between seats" , "Way between seat blocks" .)