rusty

Concise Oxford English Dictionary © 2008 Oxford University Press:
rusty/ˈrʌsti/

▶adjective (rustier, rustiest)

• 1 affected by rust.

  ■ rust-coloured.

  ■ (of black clothes) discoloured by age.

• 2 (of knowledge or a skill) impaired by lack of recent practice.

– derivatives
rustily adverb,
rustiness noun.