Definition of floor:
(n) :
the bottom or lower part of any room; the supporting surface of a room; the lower inside surface of a hollow space
"the room has a wooden floor"
(v) :
to cover (something) with a floor; to furnish (something) with a floor; to strike down or lay level (something or someone) with the floor; to knock (something or someone) down
"floor a house with pine boards"