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 WebKevin Dolak, The Hollywood Reporter, 14 June 2024
The first movie is still a flat-out genre masterpiece.
—Brian Tallerico, Vulture, 11 June 2024
Peter Sblendorio, New York Daily News, 17 Jan. 2024
Although most efficient when running flat out 24 hours a day, nuclear power plants can also operate flexibly to cover the supply gaps from wind and solar power.
—Inês Azevedo, Foreign Affairs, 13 Apr. 2020
See all Example Sentences for flat-out 
Adjective
If not for his contribution to the whip-smart writing and flat-out boldness of his long-running, raunchy yet tender, semi-autobiographical Netflix series, Big Mouth, then perhaps there’s a more compelling argument.
—Kevin Dolak, The Hollywood Reporter, 14 June 2024
The first movie is still a flat-out genre masterpiece.
—Brian Tallerico, Vulture, 11 June 2024
Adverb
Sunday’s game in Detroit should help answer this question: Was Tampa’s win over Philly more about a Bucs team finding its stride at the right time or about an Eagles team that flat out forgot how to tackle?
—Peter Sblendorio, New York Daily News, 17 Jan. 2024
Although most efficient when running flat out 24 hours a day, nuclear power plants can also operate flexibly to cover the supply gaps from wind and solar power.
—Inês Azevedo, Foreign Affairs, 13 Apr. 2020
See all Example Sentences for flat-out
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'flat-out.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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 Jun. 2024.
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