rustyoudaoicibaDictYouDict[rust 词源字典]
rust: [OE] Etymologically, rust means ‘reddened’. The word goes back ultimately to the Indo-European base *reudh- ‘red’ (source also of English red). This produced a prehistoric Germanic noun which has evolved into German and Swedish rost, Dutch roest, and English and Danish rust.
=> red[rust etymology, rust origin, 英语词源]
rust (v.)youdaoicibaDictYouDict
early 13c., from rust (n.). Transitive sense "cause to rust" is from 1590s. Related: Rusted; rusting.
rust (n.)youdaoicibaDictYouDict
"red oxide of iron," Old English rust "rust; moral canker," related to rudu "redness," from Proto-Germanic *rusta- (cognates: Frisian rust, Old High German and German rost, Middle Dutch ro(e)st), from PIE *reudh-s-to- (cognates: Lithuanian rustas "brownish," rudeti "to rust;" Latin robigo, Old Church Slavonic ruzda "rust"), from root *reudh- "red" (see red (adj.1)).

As a plant disease, attested from mid-14c. Rust Belt "decayed urban industrial areas of mid-central U.S." (1984) was popularized, if not coined, by Walter Mondale's presidential campaign.