flat-out

1 of 2

adjective

ˈflat-ˌau̇t 

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 revolution

—Nat'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

Synonyms

Adjective

• utter
• sheer
• absolute
• unconditional
• outright
• complete
• pure
• simple
• total
• definite
• damned
• damn
• downright
• perfect
• 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

Adjective

The Patriots just flat-out cut Thornton last November, figuring their 4-13 football team would be better off without a former second-round pick than with him. —Kansas City Star, 22 Sep. 2025

Now, within minutes of Kirk’s death, posts were circulating that turned out to be flat-out wrong. —Larry Magid, Mercury News, 21 Sep. 2025

Adverb

And that isn’t even factoring in Patrick Sandoval, who won’t make it back in time from Tommy John surgery; Dustin May, who underperformed before getting hurt; or Walker Buehler, who flat out didn’t work out. —Gabrielle Starr, Boston Herald, 16 Sep. 2025

The rest was just flat out ridiculous. —Alice Gibbs, MSNBC Newsweek, 7 Sep. 2025

Word History

First Known Use

Adjective

1906, in the meaning defined at sense 1

Adverb

1932, in the meaning defined at sense 1

Rhymes for flat-out

• about
• bailout
• blackout
• blowout
• breakout
• burnout
• buyout
• checkout
• closeout
• cutout
• devout
• dropout