Private cabin, say, with berth put up (9)
I believe the answer is:
stateroom
'private cabin' is the definition.
(I've seen this before)
'say with berth put up' is the wordplay.
'say' becomes 'state' ('state' can be a synonym of 'say'**).
'with' says to put letters next to each other.
'berth' becomes 'moor' ('moor' can be a synonym of 'berth').
'put up' says the letters should be written backwards.
'moor' back-to-front is 'room'.
'state'+'room'='STATEROOM'
(Other definitions for stateroom that I've seen before include "Place fit for a 27 [PRINCE]" , "Passengers's private compartment on ship" , "Luxury cabin on a liner" , "luxurious cabin" , "Private cabin on board ship" .)