(rus′tē) adjective rust·i·er, rust·i·est
1. Covered or affected with rust.
2. Consisting of or produced by rust.
3. Having the appearance of rust; having a reddish or yellowish discoloration, as from decomposition: said especially of salted fish or meat that has become, rancid.
4. Impaired by inaction or want of exercise; also, lacking nimbleness; stiff.
5 a Weakened through neglect of use: My Latin is rusty. b Having lost skill for want of practice: rusty in math.
6. Biol. Appearing as if covered with rust; brownish–red. See synonyms under TRITE. [OE rustig <rust rust]
—rust′i·ly adverb
—rust′i·ness noun

(rus′tē) adjective Brit. Dial.
Restive; stubborn; obstinate.