Flee berth? Nonsense (4)
I believe the answer is:
bunk
This clue is a triple definition!
'flee' is the first definition.
(I know that flee is a more specific form of bunk)
'berth?' is the second definition.
(synonyms)
'nonsense' is the third definition.
(I know that nonsense can be written as bunk)
(Other definitions for bunk that I've seen before include "Simple bed" , "History (said Henry Ford) - bed!" , "Utter nonsense" , "Type of bed" , "A tiered bed" .)