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.

—National 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 of flat-out

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 Aztecs took over and promptly missed a golden opportunity for a touchdown when wide-open wide receiver Nathan Acevedo flat-out dropped a pass from quarterback Jayden Denegal (8-for-16, 81 yards) at the Spartans’ 12-yard line. —Kirk Kenney, San Diego Union-Tribune, 23 Nov. 2025

Apparently, at least one player flat-out demanded that DeBoer wear the hoodie. —Matthew Schmidt, MSNBC Newsweek, 12 Nov. 2025

Adverb

Berube hasn’t just implied but said flat out that his team as a whole needs to make keeping pucks out a bigger priority. —Jonas Siegel, New York Times, 13 Nov. 2025

That’s flat out a controllable that our team knows that keeps you from winning. —Barry Jackson, Miami Herald, 31 Oct. 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