Way in or out (4)
I believe the answer is:
door
I believe this is a double definition.
'way in' is the first definition.
(I've seen this in another clue)
'out' is the second definition.
(thesaurus)
(Other definitions for door that I've seen before include "place of entry" , "Entry point" , "Alternative to knocker" , "See 1" , "Opener" .)