Merriam-Webster Collegiate Dictionary - floor

 I. noun  Usage: often attributive  Etymology: Middle English flor, from Old English flor; akin to Old High German fluor meadow, Latin planus level, and perhaps to Greek planasthai to wander  Date: before 12th century  1. the level base of a room  2.  a. the lower inside surface of a hollow structure (as a cave or bodily part)  b. a ground surface the ocean ~  3.  a. a structure dividing a building into stories; also story  b. the occupants of such a ~  4. the surface of a structure on which one travels the ~ of a bridge  5.  a. a main level space (as in a stock exchange or legislative chamber) distinguished from a platform or gallery  b. the specially prepared or marked area on which indoor sports events take place  c. the members of an assembly took questions from the ~  d. the right to address an assembly the senator from Utah has the ~  6. a lower limit ; base  • ~ed adjective  II. transitive verb  Date: 15th century  1. to cover with a ~ or ~ing  2.  a. to knock or bring down  b. flabbergast, dumbfound  3. to press (the accelerator of a vehicle) to the ~board; also to accelerate rapidly ~ed the van  • ~er noun