flat-out

1 of 2

adjective

1
: being or going at maximum effort or speed
2
: out-and-out, downright
it was a flat-out lie

flat out

2 of 2

adverb

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 : absolutely, downright
usually used as an intensive
is just flat-out confusing

Examples of flat-out in a Sentence

Adjective regarded their son-in-law as a flat-out loser and let him know it Adverb 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.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
By the end of Season Two, Deborah flat-out fires Ava, forcing her to explore new opportunities and create a new identity for herself. Kalia Richardson, Rolling Stone, 11 Mar. 2025 Iran’s supreme leader Ayatollah Khamenei, meanwhile, has flat-out refused to give up Tehran’s nuclear program and rebuffed Trump’s outreach. Natasha Turak, CNBC, 11 Mar. 2025
Adverb
The sale of those components would be banned flat out, regardless of a person’s training or vetting. Seth Klamann, The Denver Post, 2 Mar. 2025 Campbell's drive was a flat out slice heading straight OB. Mark Joseph, Newsweek, 24 Feb. 2025 See All Example Sentences for flat-out

Word History

First Known Use

Adjective

1906, in the meaning defined at sense 1

Adverb

1932, in the meaning defined at sense 1

Time Traveler
The first known use of flat-out was in 1906

Browse Nearby Words

Cite this Entry

“Flat-out.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flat-out. Accessed 16 Mar. 2025.

Last Updated: - Updated example sentences
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