flex

1 of 3

verb

ˈfleks 

flexed; flexing; flexes

transitive verb

1

: to bend especially repeatedly

2

a

: to move muscles so as to cause flexion of (a joint)

b

: to move or tense (a muscle) by contraction

3

: use, demonstrate

flexing her skills as a singer

intransitive verb

1

: bend

2

informal

a

: to talk in a boastful or aggressive way

"Bronze" is one of the most straightforward new tracks: a boastful and insidiously dark song that sees him flexing about his many wins.

—Raisa Bruner

—often used with on to indicate the person, group, etc. at whom the talk is directed

Hip-hop has never just been about selling drugs, flexing on haters, and threatening enemies, as many like to portray it.

—Aaron Williams

… he … went searching for criticism, then tried to flex on a random criticizer.

—Ashley Feinberg

"… And if President Trump is going to continue to flex on China, whether it's with tariffs, whether it's just talking tough and tweeting tough, that still draws a very stark contrast between himself and the Democratic Party. …"

—Mattie Duppler

b

: to make an ostentatious display of something : show off

While tons of influencers love to flex on Instagram via designer bags and other luxury splurges, others are all about that perfect high-low balance …

—Bella Gerard

—often used with on to indicate the person, group, etc. at whom the display is directed

It's in-your-face branding that is all about flexing on your friends in their more common, more conventional limousines.

—Max Finkel

flex

2 of 3

noun (1)

plural flexes

1

: an act or instance of flexing or bending

[Trae] Young finished with 22 points, seven assists and two steals—and a muscle flex after the game-winner.

—Chris Vivlamore

2

: flexibility, pliancy

The … fillet blade has a nice flex to it.

—Matt Foster

3

informal : an act of bragging or showing off

Monster (1994) was R.E.M.'s weird flex: an over-the-top rock album saturated with distortion, propelled by power chords and guitar feedback, and voiced by singer Michael Stipe's newly found enthusiasm.

—David Gill

flex

3 of 3

noun (2)

plural flexes

chiefly British

: an electric cord

Phrases

flex one's muscles

: to demonstrate one's strength

… an exaggerated need to flex his political muscles …

—J. P. Lash

Examples of flex in a Sentence

Verb

He flexed the muscles of his right arm.

a material that flexes easily

Recent Examples on the Web

Verb

Rogers has started flexing its financial muscles with the Blue Jays to compete with the big-spending Yankees and Red Sox in their division. —Kurt Badenhausen, Sportico.com, 2 Nov. 2025

Loop a long and heavy resistance band around both feet, keeping them flexed, and grab each open end of the band with palms facing in. —Leoni Jesner, Health, 1 Nov. 2025

Noun

Her latest chart-toppers have held steady across Halloween week — a fitting flex for a pop sorceress who’s made chart magic her signature move. —Jessica Lynch, Billboard, 31 Oct. 2025

Even more, its comfortable band flexes with your body without rolling up or digging in. —Sian Babish, PEOPLE, 25 Oct. 2025

Word History

Etymology

Verb

borrowed from Latin flexus, past participle of flectere "to cause to go in a different direction, bend, curve," of uncertain origin

Noun (1)

derivative of flex entry 1

Noun (2)

short for flexible cord

First Known Use

Verb

circa 1521, in the meaning defined at transitive sense 1

Noun (1)

circa 1934, in the meaning defined at sense 1

Noun (2)

1905, in the meaning defined above

Phrases Containing flex

• flex-cuff
• flex-fuel

Rhymes for flex

• becks
• checks
• czechs
• decks
• dex
• ex
• flecks
• hex
• lex
• necks
• pecks
• plex

Kids Definition

flex

verb

ˈfleks

1

: to bend especially over and over

2

a

: to move muscles so as to cause flexion of

b

: to move or tense (a muscle) by contraction

Medical Definition

flex

transitive verb

ˈfleks 

1

: to bend especially repeatedly

2

a

: to move muscles so as to cause flexion of (a joint)

stretching and flexing his knees

b

: to move or tense (a muscle or muscles) by contraction

flexed their biceps