RUST Meaning of RUST in English I . n. 1.Hydrated peroxide of iron.2.Mildew, blight, must, mustiness, mould. II . v. n. 1.Gather ~, become ~y, be oxidized.2.Decay, degenerate, grow dull, become sluggish. Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012