Adjective

flat (comparative flatter, superlative flattest)

Positive flat

Comparative flatter

Superlative flattest

1. Having no variations in altitude.

   The land around here is flat.

2. (of a tire or other inflated object) Deflated, especially because of a puncture.
3. (music, note) Lowered by one semitone.
4. (music) Of a note or voice, lower in pitch than it should be.
5. (music, voice) Without variations in pitch.
6. Of a carbonated drink, with all or most of its carbon dioxide having come out of solution so that the drink no longer fizzes or contains any bubbles.
7. Uninteresting.

   The party was a bit flat.

8. (wine) Lacking acidity without being sweet.
9. Absolute.

   His claim was in flat contradiction to experimental results.

   I'm not going to the party and that's flat.

10. (Slang) Describing certain features, usually the breasts or buttocks, that are extremely small or not visible at all.

    That girl is completely flat on both sides.

Synonyms

• (having no variations in altitude): even, planar, plane, smooth, uniform
• (deflated): deflated or punctured
• (without variations in pitch): monotone
• (uninteresting): boring, dull, uninteresting
• (of wine: lacking acidity): flabby

Antonyms

• (having no variations in altitude): bumpy, cratered, hilly (of terrain), rough (of a surface), wrinkled (of a surface)
• (music: lowered by one semitone): sharp
• (music: lower in pitch than it should be): sharp

Derived terms

• flat as a pancake
• flat-footed
• flat rate
• flatten
• that's flat

Flat or flats may refer to:

• Flatness, as used in different scientific and technical disciplines
• Flat (music), a symbol which denotes a lower pitch (♭)
• Flat, an apartment within a residential building
• Flat (geometry), the generalization of lines and planes in an n-dimensional Euclidean space
• Flat morphism in algebraic geometry.morphism
• A flat, two-dimensional toy soldier made of tin or plastic
• Flats (theatre), flat pieces of theatrical scenery
• Flats (USPS), an oversized letter
• Racing flats, lightweight shoes used primarily for running a race
• Flats, women's shoes with almost no heel at all
• A flat tire
• Flat, an anagram or puzzle in verse, the primary form of wordplay before crosswords came along
• Flat car, an open container on wheels designed to carry heavy loads
• Flat spot, a fault in railroad wheel shape