General English

General Science

  • noun a reddish powder that forms on the surface of iron and iron compounds on contact with damp air
  • verb to become covered with reddish powder through contact with damp air


  • noun a fungal disease that gives plants a reddish powdery covering

Cars & Driving

  • noun oxidized iron or steel, the product of corrosion
  • verb to form rust


  • Any of various powdery or scaly reddish-brown or reddish-yellow, hydrated, ferric oxides formed on the surface of iron or steel that is exposed to moisture and air. Rust eventually will weaken or destroy the material if allowed to progress.


  • noun a harmful brown discoloration to iron or steel, caused by exposure to damp air or water

Origin & History of “rust”

Etymologically, rust means ‘reddened’. The word goes back ultimately to the Indo-European base *reudh- ‘red’ (source also of English red). this produced a prehistoric Germanic noun which has evolved into German and Swedish rost, Dutch roest, and English and Danish rust.