flexion/ˈflɛkʃən/Pluralflexions1the act of bending or curving, especially of a joint or limbPhysical therapy exercises included knee flexion to improve range of motion and strengthen the leg muscles.The gymnast demonstrated exceptional spinal flexion during her backbend.Synonyms: flexureAntonyms: extension2deviation from a straight or normal courseSynonyms: inflectionflection3(grammar) the alteration of word forms to indicate differences in number, gender, case, person, tense, voice, or mood