Sleep with sailor in bunk? (5)
I believe the answer is:
roost
'sleep' is the definition.
(I've seen this before)
'sailor in bunk?' is the wordplay.
'sailor' becomes 'os' (ordinary seaman).
'in' means one lot of letters goes inside another.
'bunk?' becomes 'rot' (synonyms).
'os' going into 'rot' is 'ROOST'.
'with' is the link.
(Other definitions for roost that I've seen before include "unwelcome to come home to?" , "Bird's night-time perch" , "Colony of bats; perch" , "(Bird) settle for night" , "Where birds rest at night" .)