Man, perhaps, leaving a passage? (4)
I believe the answer is:
isle
'man perhaps' is the definition.
(Isle of Man is an example)
'leaving a passage?' is the wordplay.
'leaving' suggests deleting specific letters.
'passage?' becomes 'aisle' (aisle is a kind of passage).
'aisle' with 'a' taken away is 'ISLE'.
(Other definitions for isle that I've seen before include "Small region of land" , "Man conceivably" , "somewhere surrounded by water" , "Little land" , "Land amid water" .)