adjective rustier rust′i·er, rustiest rust′i·est

1. coated with rust, as a metal, or affected with the disease of rust, as a plant
2. consisting of or caused by rust
3. not working freely, easily, or quietly because of, or as if because of, rust; stiff or rasping in operation
4. 1. impaired by disuse, neglect, etc. to find one's golf game rusty
   2. having lost facility through lack of practice to be a little rusty in chess
5. having the color of rust
6. faded, old-looking, or shabby

Etymology: ME < OE rustig