1. a reddish-brown coating that forms on iron or steel when exposed to moisture and oxygen
2. a plant disease that causes reddish-brown spots on leaves
Usage: botany

1. to become covered with rust; to corrode
2. to deteriorate or decline from lack of use or activity

Examples

• The old car had rust spots all over its bumper.
• Salt water can cause metal to rust quickly.
• She noticed rust forming on the garden tools.
• The wheat crop was damaged by rust disease.
• Without practice, his piano skills began to rust.
• The hinges will rust if left outside in the rain.
• He scraped the rust off the bicycle chain.
• Don’t let your language skills rust from disuse.