flexion

noun

flex·​ion ˈflek-shən 

1

: the act of flexing or bending

2

: a part bent : bend

3

: inflection sense 2

4

a

: a bending movement around a joint in a limb (such as the knee or elbow) that decreases the angle between the bones of the limb at the joint compare extension sense 3b

b

: a forward raising of the arm or leg by a movement at the shoulder or hip joint

Examples of flexion in a Sentence

Recent Examples on the Web

Lauren Fichten Cameras lining the perimeter of Arthur Ashe Stadium track the ball, racket and players' limbs, collecting data points like elbow and knee flexion and wrist flex velocity. — Lauren Fichten, CBS News, 4 Sep. 2026

Seated marches encourage hip flexion, an important muscle action used when walking, climbing stairs, and even getting in and out of a car. — Rikkilynn Shields Hannigan, Health, 11 July 2026

Along the outside of the thigh, the iliotibial (IT) band — which works in conjunction with the tensor fasciae latae (TFL), a muscle involved in hip flexion and stabilisation — is visible beneath the skin. — Amelie Claydon, New York Times, 17 June 2026

The whale must use a combination of body flexion, wave energy and backward momentum to slide or thrash itself into deeper water before gravity and its own immense weight become a serious problem. — Scott Travers, Forbes.com, 2 June 2026

Word History

Etymology

borrowed from Latin flexiōn-, flexiō "act of bending or curving," from flectere "to cause to go in a different direction, bend, curve" (of uncertain origin) + -tiōn-, -tiō, suffix of verbal action

First Known Use

1615, in the meaning defined at sense 1

Rhymes for flexion

• lection
• rection
• section
• abjection
• advection
• affection
• bijection
• bisection
• collection
• complexion
• confection
• connection

Kids Definition

flexion

noun

flex·​ion ˈflek-shən 

: a bending movement around a joint (as the knee or elbow) in an arm or leg that lessens the angle between bones of the arm or leg at the joint

also : the resulting state

Medical Definition

flexion

noun

flex·​ion

variants also flection

ˈflek-shən 

1

: a bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the joint compare extension sense 2

2

: a forward raising of the arm or leg by a movement at the shoulder or hip joint