Meaning of FLAT in English

n. & v.

n. a set of rooms, usu. on one floor, used as a residence.

v.intr. (flatted, flatting) (often foll. by with) Austral. share a flat with. flatlet n.

[ alt. f. obs. flet floor, dwelling f. Gmc (as FLAT(1)) ]

Concise Oxford English dictionary.      Краткий оксфордский словарь английского языка.