Bunk on a ship (5)
I believe the answer is:
berth
'bunk on a ship' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for berth that I've seen before include "Sleeping place in ship" , "Bed on a ship/train" , "Bunk on board" , "Bed for traveller" , "Bunk in a vessel" .)