\ˈflat-ˌau̇t \

Definition of flat-out 

(Entry 1 of 2)

1 : being or going at maximum effort or speed

2 : out-and-out, downright it was a flat-out lie

flat out


Definition of flat out (Entry 2 of 2)

1 : in a blunt and direct manner : openly called flat out for revolutionNat'l Review

2 : at top speed or peak performance the car does 180 m.p.h. flat out

3 usually flat-out \ˈflat-​ˌau̇t \ : absolutely, downright usually used as an intensive is just flat-out confusing

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Examples of flat-out in a Sentence


I told him flat out that I have no intention of marrying him. We asked for more time but they refused us flat out. The car does 180 mph flat out.
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Recent Examples on the Web: Adverb

In our opinion, the ideal white elephant gift is usually one that is funny but useless, useful but bizarre, or a flat out mix of both, which can take a lot of imagination to successfully pull off. SELF, "31 Funny, Totally Office-Appropriate White Elephant Gifts $20 and Under," 8 Nov. 2018 No one in the Mariners’ organization will say flat out that another stinker would result in Hernandez’s removal from the rotation. Larry Stone, The Seattle Times, "Mariners didn’t trade for a starting pitcher, putting Felix Hernandez’s next start under microscope," 31 July 2018 Another relative echoed that claim Wednesday, contending police flat out ignored the family's warnings. James Queally, latimes.com, "Experts say there was little reason for police to intercept Nasim Aghdam before YouTube shooting," 5 Apr. 2018 Lee was sleepy, uninspired and flat out boring to watch. Womansday.com Editors, Woman's Day, "American Idol—Who Will Win?," 26 May 2010 And a pending mother of the bride who knows flat out what an illusion romance can be — and yet indulges, despite everything, in a glorious dose of why not. Karen Stabiner, New York Times, "Romancing the Stone," 2 May 2018 Trump-hating former FBI lawyer Lisa Page today did not comply with her subpoena and flat out refused to testify before a closed-door session of Congress. Fox News, "Steve Bannon on NATO: Trump is saying 'no more games'," 12 July 2018 From: Smoke&Water That line between I’m only talking about wypipo and just flat out saying all white people are bad is getting thinner and thinner Michael. Michael Harriot, The Root, "The Root’s Clapback Mailbag: The Longest Clapback Ever," 22 June 2018 The Bestia chef’s new restaurant is an oasis in the Arts District Ori Menashe may be flat out the most zealous chef in Los Angeles. Garrett Snyder, Los Angeles Magazine, "Restaurant Review: Ori Menashe’s Bavel Pushes Mideast Cuisine to New Heights," 21 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'flat-out.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of flat-out


1906, in the meaning defined at sense 1


1932, in the meaning defined at sense 1

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Statistics for flat-out

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Time Traveler for flat-out

The first known use of flat-out was in 1906

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More Definitions for flat-out



English Language Learners Definition of flat-out

 (Entry 1 of 2)

: absolute and complete

: greatest possible

flat out


English Language Learners Definition of flat out (Entry 2 of 2)

: in a very clear and direct way

: at the fastest possible speed

—used to make a statement more forceful



Kids Definition of flat-out

1 : out-right entry 2 sense 1 That's a flat-out lie.— Phyllis Reynolds Naylor, Shiloh

2 : greatest possible a flat-out effort

flat out


Kids Definition of flat out

1 : in a very clear manner I told him flat out to leave.

2 : at top speed We worked flat out to finish.

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More from Merriam-Webster on flat-out

Rhyming Dictionary: Words that rhyme with flat-out

Thesaurus: All synonyms and antonyms for flat-out

Spanish Central: Translation of flat-out

Comments on flat-out

What made you want to look up flat-out? Please tell us where you read or heard it (including the quote, if possible).


to make faulty or ineffective

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