noun a bending; a part bent; a fold.
2. flexion ·noun the act of flexing or bending; a turning.
3. flexion ·noun syntactical change of form of words, as by declension or conjugation; inflection.
4. flexion ·noun the bending of a limb or joint; that motion of a joint which gives the distal member a continually decreasing angle with the axis of the proximal part;
distinguished from extension.