ἰόομαι

A. become or be rusty, Arist. Col. 793b6, Thphr. Char. 10.14, Dsc. 5.78, Antig. Mir. 151.

2. become acrid, embittered, Hsch.:—Act. ἰόω, only late, rust, ὁ σίδηρος μᾶλλον ἰοῖ Olymp. in Mete. 266.26, cf. 270.14; convert into ἰός, Zos.Alch.pp.148,238 B.