The Oxford Thesaurus An A-Z Dictionary of Synonyms INTRO ...

lowland(s), plain(s), tundra, steppe(s), prairie(s), savannah
or savanna, heath, moor, pampas; mud-flat(s); shallow(s), shoal,
strand; marsh, bog, fen, swamp: Before us was a large flat of
barren ground. 15 rooms, suite, apartment: How can you afford
to keep a flat in London?
--adv. 16 absolutely, completely, categorically, utterly,
wholly, uncompromisingly, irrevocably, positively, definitely,
directly; exactly, precisely, flatly: He has come out flat in
favour of the status quo. When he started drinking, she left him
flat. 17 flat out. a at maximum or top or full or breakneck
speed, speedily, quickly, apace, on the run, rapidly, swiftly,
at full speed or gallop, post-haste, hell for leather, like a
bat out of hell, like a shot, like (greased) lightning, like the
wind: Someone shouted 'Fire!' and we headed flat out for the
exits. b flatly, unhesitatingly, directly, at once,
immediately, forthwith, without delay; plainly, openly, baldly,
brazenly, brashly: He asked to borrow some money and she told
him 'No', flat out.
--n. 18 room(s), flat, suite (of rooms), chambers, tenement;
garden flat, maisonette, penthouse, studio, Brit bedsitter,
bedsit; accommodation, living quarters, Colloq Brit digs , US
and Canadian apartment, furnished room, walk-up, duplex,
triplex, garden apartment: We rented a two-bedroom flat in a
good neighbourhood.
flatten v. 1 level or even (off or out); smooth (out), press or iron
(out), roll: The children's noses were flattened against the
window of the toy shop. You will have to flatten the lawn if you
want to play croquet on it. 2 knock down or over, knock out,
floor, prostrate: Menges flattened the champion in the first
round. 3 raze, tear down, demolish, level: The bomb flattened
every house in the area.
flatter v. 1 butter up, play up to, compliment, praise, fawn (on or
upon), toady to, truckle to, court, curry favour with, Colloq
flannel, soft-soap, oil; Slang shine or suck up to, boot-lick,
Taboo kiss (someone's) arse, brown-nose: Flattering the boss
won't get you a salary increase. 2 enhance, complement, suit,
show to advantage: That colour flatters her complexion. 3
cajole, wheedle, coax, inveigle, beguile, sweet-talk: He was
flattered into signing that contract.