Japanese mattress (5)
I believe the answer is:
futon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">japanese mattress</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for futon that I've seen before include "Padded unsprung mattress" , "A Japanese bed-mattress" , "Mattress used as a bed or sofa" , "Type of sofa bed" , "Japanese sofa bed" .)