rust

The deteriorated state of iron or steel as a result of moisture and oxidation; it consists mostly of iron(III) oxide (ferric oxide) and iron(II) oxide (ferrous oxide).

The rust on my bicycle chain made cycling to work very dangerous.

A similar substance based on another metal.

copper rust

A reddish-brown color.

A disease of plants caused by a reddish-brown fungus (Pucciniales).

Damage caused to stamps and album pages by a fungal infection.

To oxidize, especially of iron or steel.

The patio furniture had rusted in the wind-driven spray.

Your gold and silver have rusted, and their rust will be evidence against you and will eat your flesh like fire.

To cause to oxidize.

The wind-driven spray had thoroughly rusted the patio furniture.

To be affected with the parasitic fungus called rust.

I am sorry to say that, contrary to the majority, I have to report that the forage rusted rather badly.

To (cause to) degenerate in idleness; to make or become dull or impaired by inaction.

Must I rust in Egypt? never more / Appear in arms, and be the chief of Greece?

Of a black cat or its fur, to turn rust-coloured following long periods of exposure to sunlight.

It's very common for black cats to rust during the summer.

A surname.

A township in Montmorency County, Michigan, United States.

A municipality in Ortenaukreis, Baden-Württemberg, Germany.

A small city in Burgenland, Austria.