rust

1 rust /ˈrʌst/ noun
1 rust
/ˈrʌst/
noun
Britannica Dictionary definition of RUST
[noncount]
1 
: a reddish substance that forms on iron or some other metal usually when it comes in contact with moisture or air
2 
: a disease that causes plants to develop reddish-brown spots
3 
: a reddish-brown color
2 rust /ˈrʌst/ verb
rusts; rusted; rusting
2 rust
/ˈrʌst/
verb
rusts; rusted; rusting
Britannica Dictionary definition of RUST
1 
[no object] : to form rust : to become rusty
2 
[+ object] : to cause rust to form on (something)