—n.
1 a a reddish or yellowish-brown coating formed on iron or steel by oxidation, esp. as a result of moisture. b a similar coating on other metals.
2 a any of various plant-diseases with rust-coloured spots caused by fungi of the order Uredinales. b the fungus causing this.
3 an impaired state due to disuse or inactivity.
—v.
1 tr. & intr. affect or be affected with rust; undergo oxidation.
2 intr. (of bracken etc.) become rust-coloured.
3 intr. (of a plant) be attacked by rust.
4 intr. lose quality or efficiency by disuse or inactivity.
Derivatives:
rustless adj.
Etymology: OE rust f. Gmc
Useful english dictionary. 2012.