English Reference
adjective · noun · adverb

flat

adj. · n. · adv.
US /ˈfɫæt/ UK /flˈæt/ flat UK spelling flats, flatted

  1. 01 A2 Elementary

    adj.having a smooth surface without any parts that are higher than others.

    adj.having a horizontal surface without significant elevations or depressions.

    Simple

    The ground was perfectly flat, making it a great place to pitch our tent.

    In context

    The valley floor is remarkably flat, stretching for miles before the terrain begins to rise into the foothills.

  2. 02 A2 Elementary

    adj.having no air inside, usually because of a hole.

    adj.lacking sufficient air pressure, typically referring to a pneumatic tyre.

    Simple

    I was late for work because my bike had a flat tyre.

    In context

    The driver pulled over immediately upon realising that the rear left tyre was completely flat.

  3. 03 B1 Intermediate

    adj.describing a drink that has lost its bubbles and no longer fizzes.

    adj.lacking carbonation or effervescence due to the loss of dissolved carbon dioxide.

    Simple

    I forgot to put the cap back on the soda, and now it tastes flat.

    In context

    The champagne had been left open overnight and had gone entirely flat by the time brunch was served.

    stillvapid
  4. 04 B2 Upper Intermediate

    adj.not interesting or lacking energy.

    adj.lacking interest, excitement, or emotional variation.

    Simple

    The actor's voice was very flat, so the play felt quite boring.

    In context

    Despite the high stakes, the candidate delivered her speech in a flat, uninspiring tone that failed to move the audience.

  5. 05 B2 Upper Intermediate Music

    adj.lower in pitch than the correct note.

    adj.below the intended or true pitch; specifically, lowered by a semitone.

    Simple

    The piano sounds a bit flat, so we need to call a tuner.

    In context

    The choir director noted that the sopranos were slightly flat during the final chorus of the anthem.

  6. 06 A2 Elementary British English

    n.a set of rooms for living in that are part of a larger building.

    n.a residential suite occupying part of a building, typically on a single floor.

    Simple

    They live in a small flat on the third floor of the building.

    In context

    Finding an affordable flat in the city centre has become increasingly difficult for young professionals.

    Usage

    In British English, 'flat' is the standard word, whereas 'apartment' is more common in American English.

  7. 07 B1 Intermediate

    n.women's shoes that do not have high heels.

    n.a type of shoe with a very low or non-existent heel, usually plural.

    Simple

    She wore flats to the party because she knew she would be dancing all night.

    In context

    The dress code was formal, but she opted for elegant flats due to a recent ankle injury.

    pumpsballet shoes
  8. 08 B2 Upper Intermediate

    adv.exactly or precisely, especially when talking about time.

    adv.precisely or exactly; often used to emphasise the speed or brevity of an action.

    Simple

    He ran the race in ten seconds flat.

    In context

    The emergency crew arrived in five minutes flat, preventing the fire from spreading to the adjacent units.

  9. 09 B2 Upper Intermediate Informal

    adv.completely or absolutely, often used with 'broke' or 'refuse'.

    adv.completely or utterly; used as an intensifier for certain adjectives or verbs.

    Simple

    I can't go out tonight because I am flat broke.

    In context

    The manager flat refused to consider the proposal, citing a lack of available funding for the quarter.

Don't confuse

flat vs apartment — Flat is the standard British term for a self-contained home on one floor, while apartment is the preferred American term.

Usage flat fee


Etymology 1

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.

Etymology 2

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.

Etymology 3

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”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin French plat
Level A2 · Elementary
Frequency Common
Updated