- rust (n.)
- O.E. rust, related to rudu "redness," from P.Gmc. *rusta- (cf. Fris. rust, O.H.G., Ger. rost, M.Du. ro(e)st), from PIE *reudh-s-to- (cf. Lith. rustas "brownish," rudeti "to rust;" L. robigo, O.C.S. ruzda "rust"), from base *reudh- "red." The verb is attested from early 13c. As a plant disease, attested from mid-14c. Rust Belt "dacayed urban industrial areas of mid-central U.S." (1984) was popularized, if not coined, by Walter Mondale's presidential campaign.