Dealer uses this floor (4)
I believe the answer is:
deck
This clue is a double definition.
'dealer uses this' is the first definition.
(I know that card dealers often use decks of cards)
'floor' is the second definition.
(I know that floor can be written as deck)
(Other definitions for deck that I've seen before include "Horizontal floor on a ship" , "Ship's platform" , "Adorn; pack of cards" , "Adorn; level on ship" , "Floor on board" .)