Pass., bend oneself, double oneself up, esp. for pain, ἰδνώθη Il. 2.266; ἰδνώθη δὲ πεσών 13.618; ἰδνωθεὶς ὀπίσω, of a snake in the clutches of an eagle, 12.205; also, of one throwing up a ball perpendicularly, Od. 8.375, cf. APl. 4.97; of the womb, ἢν… ἰδνωθῇ Hp. Mul. 1.2; ἰδνοῦται ib. 10; — Act., ἰδνῶ only in Hdn. Gr. 1.451.