1
: in a blunt and direct manner : openly
called flat out for revolution—
Nat'l Review
Nat'l Review2
: 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
Synonyms
Adjective
- absolute
- all-out
- arrant
- blank
- blooming [chiefly British]
- bodacious [Southern & Midland]
- categorical
- categoric
- clean
- complete
- consummate
- crashing
- damn
- damned
- dead
- deadly
- definite
- downright
- dreadful
- fair
- flat
- out-and-out
- outright
- perfect
- plumb
- profound
- pure
- rank
- regular
- sheer
- simple
- stark
- stone
- straight-out
- thorough
- thoroughgoing
- total
- unadulterated
- unalloyed
- unconditional
- unmitigated
- unqualified
- utter
- very
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
Michael-Shawn Dugar, The Athletic, 24 Dec. 2024
Williams reportedly denied any knowledge or involvement while Simon flat-out refused to speak to police.
—Nate Gartrell, The Mercury News, 21 Dec. 2024
Daniel R. Depetris, Newsweek, 7 Dec. 2024
But several Democrats cautioned Biden against doing so or flat out rejected the idea.
—Rebecca Beitsch, The Hill, 7 Dec. 2024
See all Example Sentences for flat-out 
Examples are automatically compiled from online sources to
show current usage.
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Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
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Adjective
Macdonald could have given Sam Howell the benefit of the doubt for his poor showing in relief duty in Week 15 but chose to flat-out say the backup quarterback didn’t play very well.
—Michael-Shawn Dugar, The Athletic, 24 Dec. 2024
Williams reportedly denied any knowledge or involvement while Simon flat-out refused to speak to police.
—Nate Gartrell, The Mercury News, 21 Dec. 2024
Adverb
Following reports that Syrian President Bashar al-Assad has fled Damascus in the face of an insurgent offensive on the capital, which the Syrian government has flat out denied, Trump offered his insight on the crisis.
—Daniel R. Depetris, Newsweek, 7 Dec. 2024
But several Democrats cautioned Biden against doing so or flat out rejected the idea.
—Rebecca Beitsch, The Hill, 7 Dec. 2024
See all Example Sentences for flat-out
Articles Related to flat-out
Dictionary Entries Near flat-out
Cite this Entry
“Flat-out.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flat-out. Accessed 30 Dec. 2024.
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