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

• 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

Adjective

Advertisement The newspapers’ divorce stories of the 1950s were flat-out lurid. —Patt Morrison, Los Angeles Times, 24 May 2024

Florida got level at 1-1 6:23 into the second period when Sam Reinhart’s wrist shot flat-out beat Jeremy Swayman. —Greg Cote, Miami Herald, 15 May 2024

Word History

First Known Use

Adjective

1906, in the meaning defined at sense 1

Adverb

1932, in the meaning defined at sense 1