- rust (v.)
- early 13c., from rust (n.). As a plant disease, attested from mid-14c. Related: Rusted; rusting.
- rust (n.)
- Old English rust, related to rudu "redness," from Proto-Germanic *rusta- (cf. Frisian rust, Old High German and German rost, Middle Dutch ro(e)st), from PIE *reudh-s-to- (cf. Lithuanian rustas "brownish," rudeti "to rust;" Latin robigo, Old Church Slavonic ruzda "rust"), from root *reudh- "red" (see red (1)). Rust Belt "dacayed urban industrial areas of mid-central U.S." (1984) was popularized, if not coined, by Walter Mondale's presidential campaign.