to bend, as a part of the body: He flexed his arms to show off his muscles.
to tighten (a muscle) by contraction.
to demonstrate (one’s ability, expertise, etc.): She’s flexed her marketing skills for various clients in the publishing industry.
Slang. to boast or brag about; flaunt: He’s just not into flexing his success.
verb (used without object)
to bend.
Slang. to boast or brag; show off: In his rap lyrics he flexes about his fancy lifestyle.
noun
the act of flexing.
Slang. a boast or brag: It's not a flex, but we have the best burgers here.
British.
any flexible, insulated electric cord; an electric cord or extension cord.
Slang.an elastic band, as a garter.
Mathematics. an inflection point.
Verb Phrases
flex on,Slang. to brag or show off to; assert one’s dominance or superiority over: She’s flexing on her haters by posting new photos of her beautiful family.
Origin of flex
1
First recorded in 1515–25; (adjective) from Latin flexus, past participle of flectere “to bend, turn”; (noun) from Latin flexus act of bending, equivalent to flect(ere) + -tus suffix of verbal action
The moon is believed to be a geologically active world, like the Earth, because the strong tidal flexing heats its rocky, metallic interior and keeps it partially molten.
The Four Most Promising Worlds for Alien Life in the Solar System|Gareth Dorrian|September 24, 2020|Singularity Hub
This thick bag is made of a durable fabric with a waterproof finish and has an outer surface that flexes to the shape of the contents within, making it a good choice for comprehensive protection of irregularly shaped items.
The best under-bed storage solutions|PopSci Commerce Team|September 9, 2020|Popular Science
Similarly, as a first-time CEO, I often have to flex muscles I’ve never used before.
Book recommendations from Fortune’s 40 under 40 in finance|Rachel King|September 8, 2020|Fortune
Omnicom CEO John Wren, who has already cut 6,100 jobs, told analysts last month that each one of the holding group’s individual offices has action plans in place that “flex up and down” in response to ad spending.
The second wave of agency staff cost cuts is starting to build — but it might not crash as hard as the spring swell|Seb Joseph|August 13, 2020|Digiday
They’re starting to flex that muscle, with demands from athletes in the Pac 12 and Big Ten conferences that mix health and safety with racial and economic justice, combined with a threat not to play if their demands aren’t met.
Is School Out Forever?|Daniel Malloy|August 9, 2020|Ozy
When it comes to tangible gifts, the sharing economy really starts to flex its holiday disrupting muscle.
One of a Kind Gifts Are Only a Neighbor Away|Lawrence Ferber|December 8, 2014|DAILY BEAST
Unlike Bond, constantly thwarting Soviet villains, Burlington never got a chance to flex its muscle.