LSJ
Pass., become rusty, tarnished, LXX Si. 12.11 (Act. is v.l.), Str. 16.2.42, Ep. Jac. 5.3, Dsc. 4.82, Arr. Epict. 4.6.14; metaph, βασιλεία σιδηρᾶ καὶ ιωμένη D.C. 71.36.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
TBESG
κατ-ιόω, -ῶ
(intensive of ἰόω; < ἰός) [in LXX: Sir.12:11 * ;]
to rust over; pass., become rusted over: Jas.5:3.†
(AS)
Translators Brief lexicon of Extended Strongs for Greek based on Abbot-Smith, A Manual Greek Lexicon of the New Testament (1922) (=AS), with corrections and adapted by Tyndale Scholars