flat
n. countablen. A set of rooms for living in, usually on one floor of a larger building. It's the word people in the UK often use for what Americans call an apartment.
n. A self-contained residential unit that is part of a larger building. This term is standard in British English, with 'apartment' being the common American English equivalent.
She lives in a small flat.
They are looking for a two-bedroom flat to rent near the city centre.
The penthouse flat offered panoramic views of the skyline, but its stark, minimalist interior felt less like a home than a gallery.
From Middle English flat, a borrowing from Old Norse flatr (compare Norwegian and Swedish flat, Danish flad), from Proto-Germanic flataz, from Proto-Indo-European pleth₂- (“flat”); akin to Saterland Frisian flot (“smooth”), German Flöz (“a geological layer”), Ancient Greek πλατύς (platús), Latvian plats, Sanskrit प्रथस् (prathas, “extension”). Doublet of plat and pleyt. The noun is from Middle English flat (“level piece of ground, flat edge of a weapon”), from the adjective. The algebraic sense was coined by Serre in a 1956 paper, originally as French plat.
From an alteration (due to Scots flatt (“a level part of a structure”)) of Scots flet, flett (“inner part of a house”), from Middle English flet (“dwelling”), from Old English flet, flett (“ground floor, dwelling”), from Proto-West Germanic flati, from Proto-Germanic flatją (“floor”), from Proto-Germanic flataz (“flat”), from Proto-Indo-European pleth₂- (“flat”). Akin to Old Frisian flet, flette (“dwelling, house”). More at flet, flat₁.
From Middle English flatten, from Old French flatir (“to knock or strike down, dash”), from Frankish flattjan (“to move the palm of the hand”), from Proto-Germanic flatjaną (“to make flat, flatten”).