rust

noun

1. 1

   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.

2. 2

   A similar substance based on another metal.

   copper rust

3. 3

   A reddish-brown color.

4. 4

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

5. 5

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

verb

1. 1

   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.

   The relegation of locomotives to storage seemed to be on a very unsystematic basis on all three principal Irish railways: while one member of a class was rusting in a yard, another might be hard at work in revenue-earning service—[…].

2. 2

   To cause to oxidize.

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

3. 3

   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.

4. 4

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

   My knowledge of Spanish has rusted over the years.

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

5. 5

   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.

Forms

plural

rusts

past tense

rusted

past participle

rusted

present participle

rusting

third person singular

rusts