rust

Fetched 2026-10-27 (live).

Datamuse reports no synonyms or antonyms for this word.

Noun

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. A similar substance based on another metal.
   • copper rust
3. A reddish-brown color.
   • rust:
4. A disease of plants caused by a reddish-brown fungus (Pucciniales).
5. Damage caused to stamps and album pages by a fungal infection.

Verb

1. To oxidize, especially of iron or steel.
   • The patio furniture had rusted in the wind-driven spray.
2. To cause to oxidize.
   • The wind-driven spray had thoroughly rusted the patio furniture.
3. To be affected with the parasitic fungus called rust.
4. To (cause to) degenerate in idleness; to make or become dull or impaired by inaction.
   • My knowledge of Spanish has rusted over the years.
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.

Source: Wiktionary · CC BY-SA 3.0 (Wiktionary) · cached copy, not a rewrite.