intransitive verb
Definition: To undergo a process of corrosion or decay, often resulting in a reddish-brown color, typically due to exposure to moisture and air.
Example: The old bicycle began to rust after being left outside in the rain for weeks.
noun
Definition: A reddish-brown coating that forms on iron and other metals when they corrode, often due to moisture and oxygen. It can also refer to a plant disease caused by certain fungi that leaves spots on plants.
Example: The old bike was covered in rust after being left outside for years.
transitive verb
Definition: To cause a metal to develop a reddish-brown coating due to oxidation, often from exposure to moisture or air.
Example: The rain will rust the old bicycle if it is left outside.