noun

rust

ruhst

noun

The reddish-brown coating that forms on iron or steel when it reacts with moisture and oxygen over time.

"The old bike chain was covered in rust after sitting out in the rain all winter."

"She scraped the rust off the gate before repainting it."

A reddish-brown color, named after the corrosion.

"The autumn leaves turned a deep rust color."

verb

To corrode or become covered in rust, or to cause something to do so.

"Leave that tool out in the damp and it will rust within weeks."

"Road salt rusts car bodywork much faster than fresh water does."

To lose sharpness or ability through lack of use.

"His French had rusted after a decade of not speaking it."

How to Use Rust

Learner’s notes

In plain EnglishThe reddish coating that eats away at metal when it is exposed to air and water, or (as a verb) for a skill to go stale from disuse.

Common mistake

When talking about a skill, "rusty" (adjective) is far more common than "rusted" — "my Spanish is rusty," not "my Spanish is rusted."

Common pairings

rust away covered in rust rust spots prevent rust

rusted past tense, rusts plural, Rusts plural, rusts singular

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The old bike chain was covered in _____ after sitting out in the rain all winter.

From Old English rust, going back to a very old Germanic root meaning "red" — the same root that gives us the word "red" itself.

oxidise oxidize corrode

bust dust must lust just oust gust trust crust joust Faust Foust

oxidise oxidize corrode