Covered with rust, which is the reddish-brown coating that forms on iron or steel when it reacts with oxygen and water.
From Old English 'rust,' possibly related to Old Norse 'rostr.' Rust is the chemical process called oxidation, and the word describes things affected by this process.
Rust is basically controlled burning—it's the same chemical reaction as fire, but so slow you can't see it burning; the Statue of Liberty's green color is actually a type of rust called patina!
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