Ship's floor (4)
I believe the answer is:
deck
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ship's floor</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for deck that I've seen before include "Pack - embellish - ship's floor" , "Pack of cards (US)" , "part of ship" , "Dress; floor; cards" , "Pack of playing cards on board" .)