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”).
flat (comparative flatter, superlative flattest)
- Having no variations in height.
- (music, voice) Without variations in pitch.
- (slang) Describing certain features, usually the breasts and/or buttocks, that are extremely small or not visible at all.
- (music, note) Lowered by one semitone.
- (music) Of a note or voice, lower in pitch than it should be.
- (of a tire or other inflated object) Deflated, especially because of a puncture.
- 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.
- (wine) Lacking acidity without being sweet.
- (of a battery) Unable to emit power; dead.
- (juggling, of a throw) Without spin; spinless.
- (figuratively) Lacking liveliness or action; depressed; dull and boring.
- Absolute; downright; peremptory.
- (phonetics, dated, of a consonant) sonant; vocal, as distinguished from a sharp (non-sonant) consonant
- (grammar) Not having an inflectional ending or sign, such as a noun used as an adjective, or an adjective as an adverb, without the addition of a formative suffix; or an infinitive without the sign "to".
- (golf, of a golf club) Having a head at a very obtuse angle to the shaft.
- (horticulture, of certain fruits) Flattening at the ends.
- (authorship, figuratively, esp. of a character) Lacking in depth, substance, or believability; underdeveloped; one-dimensional.
flat (comparative more flat, superlative most flat)
- So as to be flat.
- (with units of time, distance, etc) Not exceeding.
- Directly; flatly.
- (finance, slang) Without allowance for accrued interest.
From 1795, alteration of Scots flet (“inner part of a house”), from Middle English flet (“dwelling”), from Old English flet, flett (“ground floor, dwelling”), from Proto-Germanic *flatją (“floor”), from Proto-Germanic *flataz (“flat”), from Proto-Indo-European *plat- (“flat”). Akin to Old Frisian flet, flette (“dwelling, house”). More at flet, flat1.
flat (plural flats)
- (chiefly Britain, New England, New Zealand and Australia, archaic elsewhere) An apartment, usually on one level and usually consisting of more than one room.
From Middle English flatten, from Old French flatir (“to knock or strike down, dash”).
flat (third-person singular simple present flats, present participle flatting, simple past and past participle flatted)
- (transitive, obsolete) To beat or strike; pound
- (transitive) To dash or throw
- (intransitive) To dash, rush