1. A red or brown oxide coating on iron or steel caused by the action of oxygen and moisture
   "The old car was covered in rust"
    
2. The formation of reddish-brown ferric oxides on iron by low-temperature oxidation in the presence of water
   "Rust appeared on the car's fenders after the wet winter";
   - rusting
    
3. A strong reddish-brown colour
   "The autumn leaves turned a deep rust colour"
    
4. A plant disease that produces a reddish-brown discolouration of leaves and stems; caused by various rust fungi
   "The farmer's wheat crop was severely affected by rust"
    
5. Any of various fungi causing rust disease in plants
   "The rust fungus left orange spots on the wheat leaves";
   - rust fungus
    
6. A reddish-brown colour
   "The autumn leaves turned a beautiful shade of rust"

1. Become destroyed by water, air, or a corrosive such as an acid
   "The pipes rusted";
   - corrode
    
2. Become coated with oxide
   "The old car rusted in the damp garage"
    
3. Cause to deteriorate due to the action of water, air, or an acid
   "The steady dripping of water rusted the metal stopper in the sink";
   - corrode, eat

1. Of the brown colour of rust
   "The rust-brown leaves crunched underfoot";
   - rusty, rust-brown

Derived forms: rusts, rusting, rusted

See also: chromatic

Type of: brown, brownness, corroding, corrosion, crumble, damage, decay, dilapidate, erosion, ferric oxide, fungus, oxidate, oxidation, oxidisation [Brit], oxidise [Brit], oxidization, oxidize, plant disease, red, redness

Part of: order Uredinales, Uredinales

Encyclopedia: Rust, Michigan