Definition of flex in English:



  • 1 Bend (a limb or joint)

    [with object] ‘she saw him flex his ankle and wince’
    • ‘Throughout the match he struggled to unleash the ball in excess of 100 mph, and more than once he flexed the troublesome joint while grimacing in pain.’
    • ‘Over the last few days I've been thinking about all the things I won't be able to do with the limb; flex my ankle, wiggle my toes, point my foot left and right.’
    • ‘Thanks to exercise classes, an eighty-something tests a newly replaced knee and another happily flexes both arthritic ankles.’
    • ‘And yes, while the splendour of Holme oaks, Magnolia grandiflora, Acacia and Eucalyptus is undisputed, they must be allowed room to flex their limbs to best advantage.’
    • ‘Kel gingerly flexed the fingers of her right hand while her mind raced for an answer.’
    • ‘As you initiate your turn your leg should be long with your hips up. Work the turn from there by flexing your ankles first then your knees next until you reach the end of your turn.’
    • ‘All these bones articulate with other bones and are able to make tiny interdependent movements, as well as bend or flex themselves.’
    • ‘As you flex your ankles, knees and hips, the angle of your front shin with the ground should match the angle of your spine with the ground.’
    • ‘I sat up slowly from my huddled position in the corner, flexing my pained ankle experimentally, and my movement caught the attention of my protector.’
    • ‘Land softly by flexing your ankles, as if you were in a second floor apartment and didn't want to wake your neighbors downstairs.’
    • ‘She groaned as she flexed her right ankle, it figured, she'd twisted it when she fell.’
    • ‘The boy gingerly flexed his fingers; testing out his healed hand… everything seemed fine.’
    • ‘Then flex your wrists to bring your fingertips toward your chest.’
    • ‘He listens to my belly, then takes me by the ankle, extending and flexing my hip.’
    • ‘Gently flex your left foot and rotate your hip outward so that your foot is pointing to 11 o'clock.’
    • ‘Exercising the calf muscles every half hour while seated by spending a few minutes flexing and rotating the ankles is also recommended to reduce the effects of stasis.’
    • ‘Sitting at one of the long plastic tables in the cafeteria, Chelsea Stanford takes the opportunity to flex her ankle a few times.’
    • ‘Bend the main joint, flex another smaller joint to propel the body forward, then stop the motion by repeating it again.’
    • ‘As you flex your ankle, knee, and hip, your core will fall forward.’
    • ‘He flexed his ankle, silently thanking God that it had held out thus far in the evening.’
    bend, curve, crook, hook, cock, angle, kink, buckle, double up
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    1. 1.1[no object](of a limb or joint) become bent.
      ‘prevent the damaged wrist from flexing’
      • ‘The man-beast pounced and her left hand flexed out in panic, she had nothing planned.’
      • ‘The arm remains extended throughout the aerial phase until it flexes slightly at touchdown.’
      • ‘Simultaneously, he thrusts his shooting arm to full extension, his hand and fingers flexing downward at the wrist in order to impart a gentle backspin as the ball is released.’
      • ‘The soldier's ankle flexed - a sign that the stimulator had found the nerves serving the injured area.’
      • ‘He moaned slightly, his wings flexing involuntarily, sending a few feathers swirling around them.’
      • ‘Beginning and intermediate skaters tend to flex more at the waist with little bend in the ankles.’
      • ‘Stepping out of his dark blue 1976 convertible, David walked slowly up the driveway, steadily ignoring the way his left hand flexed in and out of a fist.’
      • ‘My fingers flexed into fists and my fists pressed into my thighs as I counted to ten.’
      • ‘Brazen anger flashed into her eyes, hands flexing into fists.’
      • ‘Bat wings flexed with anticipation and forked prehensile tails of slick amphibian flesh twitched behind them.’
      • ‘Her breath caught in her chest as her hands flexed, the fingers tingled.’
      • ‘His hands flexed into fists at his sides before the fingers slowly relaxed.’
      • ‘His wings itched to be shown, and his hands flexed and unflexed into fists, as he forced himself not to step in.’
      • ‘She reached up with both hands and captured his face, her fingers flexing on his skin.’
      • ‘Her fingers flexed like the arms and legs of a ballet dancer, fingernails glossy pink, although never polished or buffed.’
      • ‘With feet flexed and hands protruding from the fabric, dancers' limbs were indistinguishable from each other.’
      • ‘He hung there suspended, his wings flexed to three-quarters of their span, and then fully spread as the wind bore him away.’
      • ‘The stiff plastic keeps your ankles flexed forward and prevents you from turning your ankles out or in.’
      • ‘His arm soon extended fully, and his hand was slowly flexing.’
      • ‘She braided them tightly, pulling until her fingers turned white against the rope and her arms flexed and shook.’
      bend, curve, crook, hook, cock, angle, kink, buckle, double up
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    2. 1.2Cause (a muscle) to stand out by contracting or tensing it.
      ‘bodybuilders flexing their muscles’
      • ‘The farm lobby and employers in other industries are now flexing their muscle even more - hoping to expand the number of guestworkers and relax the rules currently in place.’
      • ‘This had been a clear case of the Bulls flexing their considerable muscle (and finding new muscles they didn't think they had) ahead of this week's grudge match against the Rhinos.’
      • ‘Anyway, Josh ran his fingers through his golden curls and subtly flexed his biceps.’
      • ‘Builders in this country (if they can find enough of them) are well known for flexing their muscle for extra money when things are running late, over budget and completion is near.’
      • ‘Flex your biceps throughout each rep to make the movement stricter and harder.’
      • ‘Paul was standing in front of a mirror flexing his invisible muscles without a shirt on.’
      • ‘I stand on my tip-toes and flex every muscle in my body that I can.’
      • ‘Every day, as part of my idiosyncratic diet and fitness regime, I jog past Muscle Beach on my way to the pizza parlour - while muscular guys flex their pecs at me in disgust.’
      • ‘My Dad kept an old photo in his sock drawer of himself on muscle-beach, shirtless, flexing his biceps…’
      • ‘The sun rose from behind the buildings, like a troll flexing his muscles.’
      • ‘Analysts say the former body builder and Hollywood icon is flexing political muscles not seen for years in California.’
      • ‘Williams also enjoys flexing her acting muscles.’
      • ‘The muscular fellow grinned at the women gathered on both sides of the cheetah and then flexed his muscles.’
      • ‘‘I'm rich beyond my wildest dreams,’ he told the gathered throng, flexing the muscles and exercising the tattoos exposed by his Motley Crue singlet.’
      • ‘But it is eerily impressive, like watching a brilliant young bodybuilder flexing his steroidal muscles.’
      • ‘Ask a five-year-old to ‘make a muscle,’ and he'll automatically flex his biceps.’
      • ‘Five of my football buddies and I stood hunched over flexing our biceps.’
      • ‘Loveable cartoon character Popeye always flexes his biceps when he wants to show off his muscles.’
      • ‘They stood before them, flexing their godly muscles.’
      • ‘But in his spare time the fitness fan endures a gruelling exercise and diet regime to ensure he is a top-class body-builder and he is now in the process of flexing his pecs to take on Europe and the World.’
      tighten, tauten, make taut, tension, contract, stiffen, brace, knot
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    3. 1.3[no object](of a muscle) contract or be tensed.
      ‘a muscle flexed in his jaw’
      • ‘Rockus appeared through the doorway, his muscles flexing with adrenaline.’
      • ‘End the movement with the dumbbell over your upper chest and with your pec muscles flexed as hard as possible.’
      • ‘Start with your body motionless, your legs hanging down and your abs slightly flexed.’
      • ‘The man continued to stare, the muscles of his jaw flexing.’
      • ‘Muscles flexing, waiting, twitching, he has pounced on a starling, dispatched it with a single bite, and carried the limp lifeless thing away.’
      • ‘His muscles flexed to where you could see the very veins popping out.’
      • ‘His muscles flexed and tensed and for a moment, Lena thought that this is what the gods had made him for.’
      • ‘Next, you're warm because that big heart muscle is flexing maybe two, three times a second.’
      • ‘In the dull, blue silence, time slows, muscles twist and flex, ribs contract.’
      • ‘Jim's jaw muscle flexed and he continued to unwrap the shirt bits from Blair's arm.’
      • ‘I noticed how his calf muscles would flex as he pedalled.’
      • ‘He yawned and stretched, muscles flexing as he did so.’
      • ‘Quinn shouted back, his muscles flexing as he forced Rolandon back onto the door.’
      • ‘Slowly but surely the pale man, his muscles flexing under tight pale skin, walked to me.’
      • ‘Greg could see Vincent's muscles flexing, the sword pushing out against the wires wrapping around it, stretching the metal cord.’
      • ‘He was still standing there when she went back into her room, his arms crossed, the thick muscles of his biceps flexing.’
      • ‘His tears became his master, his chest heaved, his muscles flexed and tightened, his teeth clenched threatening to break his jaw bone.’
      • ‘Her muscles flexed at every move, growing tired.’
      • ‘She feels his muscles flexing from time to time across her skin and he can feel her soft fur.’
      • ‘Paula said you have a muscle flexing in your throat.’
    4. 1.4[no object](of a material) be capable of warping or bending and then reverting to shape.
      ‘set windows in rubber so they flex during an earthquake’
      • ‘When metal flexes, it makes noise, like a metal clicker toy.’
      • ‘The same property of the material that allows it to flex under recoil will also make it return to its original position when the recoil stress is passed.’
      • ‘The decks expand by four centimetres, the arch can flex by eighteen depending on temperature.’
      • ‘But when magnetic force pulls on the spider, it flexes like a pie tin, snapping away from the seat to open the valve.’
      • ‘The property of elasticity allows the ball to retain kinetic energy during a collision by having the ability to flex without breaking and then return to its original shape.’
      • ‘The air flexed outwards from the tip of the staff, stealing the breath from the room.’
      • ‘We realized that fabric ducts would solve several of these problems because of their lower weight and because they can easily flex with building movement.’
      • ‘His right hand grasped slightly against the three match books, and their delicate paper flexed slightly.’
      • ‘An experienced player can tell by the stick's vibration whether or not the stick flexes too much.’
      • ‘Members were inclined to apply the architects' description of bamboo as ‘a material that flexes but does not fracture’ to the school as a model for others.’
      • ‘I could hear it sing out and howl as the metals within twisted and bent, flexing with the current.’
      • ‘The inner timber tracery is carried by the steel structure and will flex with the steel stems.’
      • ‘Over time, as the boot leather flexes, stiffness decreases.’
      • ‘For example, when pushing RAM into any of the slots, the board will flex alarmingly due to not being supported on the extreme right side.’
      • ‘This does mean that you need to take a little care when plugging in drive connectors, as the board may flex a bit.’
      • ‘I recall a car that flexed and twisted around corners so much that it was noticeable through the steering wheel.’
      • ‘His Bilbao Guggenheim showed the potential of a seemingly incorrosible material, flexing shiny in the sun.’
      • ‘Following the sound of flexing paper, there were two sharp intakes of breath and the light was mercifully aimed lower, pointing at his feet.’
      • ‘Any roofless car will flex in the bends and on oddly-cambered roads, and the 307 CC is no exception.’
      • ‘A collective puff of expelled breath flexed through the courtyard, liberated pirates rubbing their eyes to be certain the welcome, if not morbid, sight was real.’
    5. 1.5Archaeology Place (a corpse) with the legs drawn up under the chin.
      ‘a flexed burial’
      • ‘Some adults and children were subject to secondary processing after initial burial in flexed or extended positions in pits located inside the house.’
      • ‘They did, however, think the skeletons looked very unusual, being very highly flexed, like Peruvian mummies.’
      • ‘Despite the length of the pit, the proximity of these articulated extremities and the ilium shows that the primary burial was in a flexed position prior to disturbance.’
      • ‘Based on the total burial count, this list provides a 3: 5 ratio of flexed to bundled burials.’
      • ‘The mortuary program incorporated a variety of burial modes, including extended and flexed primary, bundle, and cremation.’


  • The action or state of flexing.

    ‘add rigidity and eliminate brake flex’
    • ‘It is great at fighting flex, but it's heavy, ugly (in our opinion) and offers the fewest set up options offered by threadless stems.’
    • ‘Too much carbon wrapped around the barrel reduces the spring, making the bat too stiff, while an excess of fiberglass laid lengthwise would create too much flex.’
    • ‘For starters, the chainstays and seatstays have very nice dampening properties due to their S-Bend design, yet retain their ability to deflect torsional flex.’
    • ‘One's shifts are laser-sharp every time, while the other's flex sometimes causes hesitation.’
    • ‘It's also extremely supple and fast, boasting lots of flex and weighing just 10.2 ounces.’
    • ‘There's just enough flex for smoothing out chunky, frozen corn without being too soft for belly-drag carves.’
    • ‘It is stiff, but does allow enough flex for striding.’
    • ‘In addition, the heel piece locks down in such a way that it cannot prerelease due to flex of the ski, and the touring heel lifter can't be inadvertently raised while downhill skiing.’
    • ‘And what design considerations were made to handle any flex?’
    • ‘This new Kenda has low, square knobs that eliminate knob flex and give positive, predictable traction on even the hardest surfaces.’
    • ‘It should combine a powerful butt with sufficient tip flex for casting the intended lure.’
    • ‘Is farther or closer better for preventing flex?’
    • ‘While we wouldn't call it a noodle, it's not stunningly stiff: If you really yank on the hoods during a tough climb or torque the drops in a sprint, you feel flex.’
    • ‘Different strength springs providing different degrees of flex are available and selected according to the weight of the skier, not unlike an actual cross country ski.’
    • ‘The Revolver features a no-link rear dropout, so the entire rear triangle swings rigidly with only slight vertical flex required to follow the shock path.’
    • ‘The design adds tremendous strength to your whitewater stroke while retaining perfect flex.’
    • ‘ICC regulations state that pace bowlers are allowed 10 degrees of flex, medium pacers 7 1/2 degrees and spinners five.’
    • ‘A ski this light with such forgiving flex would normally chatter out at the apex of a turn.’
    • ‘The idea is to stabilize the scope tube and eliminate tube flex, which is still disaster for a scope.’
    • ‘Surfers with experience pre-dating bodyboards are starting to re-investigate the limits of flex with custom surfmats.’


  • flex one's muscles

    • Give a show of strength or power.

      • ‘Committees are also flexing their muscles in ways ministers are struggling to predict.’
      • ‘Now they are flexing their muscles, increasingly conscious of their strength and ever more radical in their demands.’
      • ‘So at some stage you have to lay down the law and your kids will see it as you flexing your muscles and being unkind to them but in reality you are just teaching them for the future or protecting them.’
      • ‘And who can forget the imperial powers flexing their muscles - Mussolini's Italy invading Ethiopia, Hitler's Germany making its territorial advances in Europe.’
      • ‘History often provides an opportunity for political outfits to flex their muscles and resort to a show of pomp to impress a wavering rank and file.’
      • ‘But the US regulators are also flexing their muscles and seeking to impose their standards on other markets around the world.’
      • ‘The so-called ‘dwarfs’ of the EU flexed their muscles at the Athens summit yesterday and insisted their opposition to a permanent and single EU president must be heeded.’
      • ‘They routinely flexed their muscles in the form of politically-motivated strikes, most significantly in the early 1970s when they helped bring down Edward Heath's Conservative government.’
      • ‘Superpowers flexed their muscles figuratively in the space race and literally at the Olympics.’
      • ‘Now that Labour is safely back in power, the public sector unions have already started to flex their muscles.’


Early 16th century: from Latin flex- bent from the verb flectere.