Lexical Definition

‎κατιόω‎ katióō (kat-ee-o'-o) to corrode ^G:V
from ‎κατά‎ and a derivative of ‎ἰός‎

canker.

• to rust down, i.e. corrode

Abbott-Smith

**† κατ-ιόω, -ῶ (intensive of ἰόω; < ἰός), [in LXX: Si 12:11*;]
to rust over; pass., become rusted over: Ja 5:3.†

Abbott-Smith References

Liddell-Scott-Jones

κατιόομαι,

passive, become rusty, tarnished, [LXX+1st c.BC+]

_{LSJ Scripture Refs: Jas.5.3}