1having a level surface; without raised areas or indentations:he sat down on a flat rock trim the surface of the cake to make it completely flat (of land) without hills:thirty-five acres of flat countryside (of an expanse of water) calm and without waves. not sloping:the flat roof of a garage having a broad level surface but little height or depth; shallow:a flat rectangular box a flat cap (of shoes) without heels or with very low heels. 2lacking emotion; dull and lifeless:‘I’m sorry,’ he said, in a flat voice (of a person) without energy or enthusiasm:his sense of intoxication wore off until he felt flat and weary (of trade, prices, etc.) not showing much activity; sluggish:the UK housing market was flat (of a colour) uniform:a flat shade of grey (of a photograph or negative) lacking contrast. 3(of a sparkling drink) having lost its effervescence: she sipped some of the flat champagne (of something kept inflated, especially a tyre) having lost some or all of its air, typically because of a puncture. British (of a battery) having exhausted its charge. 4 [attributive] (of a fee, wage, or price) the same in all cases, not varying with changed conditions or in particular cases:a flat fare of £2.50See also flat rate. (of a denial, contradiction, or refusal) completely definite and firm; absolute:the request was met with a flat refusal 5(of musical sound) below true or normal pitch. [postpositive] (of a key) having a flat or flats in the signature. [postpositive] (of a note) a semitone lower than a specified note:E flat
6 (Flat) relating to flat racing:the Flat season 1in or to a horizontal position:he was lying flat on his back she had been knocked flat by the blast lying in close juxtaposition, especially against another surface:his black curly hair was blown flat across his skull so as to become smooth and even:I hammered the metal flat 2 informal completely; absolutely:I thought you’d turn me down flat [as submodifier]:Myers was flat broke used with an expression of time to emphasize how quickly something can be done or has been done:you can prepare a healthy meal in ten minutes flat
3below the true or normal pitch of musical sound: it wasn’t a question of singing flat, but of simply singing the wrong notes
1 [in singular] the flat part of something:she placed the flat of her hand over her glass
) an area of low level ground, especially near water:the shingle flats of the lake
North American a shallow container in which seedlings are grown and sold. a shoe with a very low heel or no heel: she wore black leggings, a white strapless dress, and a pair of electric blue flats a railway wagon with a flat floor and no sides or roof; a flatcar. 2
) an upright section of stage scenery mounted on a movable frame.
, chiefly North American a flat tyre: I’ve got a flat—there were nails under the wheel
4 (the Flat) British flat racing.
5a musical note lowered a semitone below natural pitch. the sign (♭) indicating a flat. 1
(usually as adjective flatted
, North American lower (a note) by a semitone:‘blue’ harmony emphasizing the flatted third and seventh
2 archaic make flat; flatten:flat the loaves down
1as fast or as hard as possible:the whole team is working flat out to satisfy demand 2 informal
, chiefly North American without hesitation or reservation:she flat out said she didn’t trust her fellow board members (as adjective flat-out)flat-out perjury
3lying stretched out, especially asleep or in a state of exhaustion: he lay flat out, breathing heavily