rust

Universal Words noun, verb noun [U] 1 a reddish-brown substance that is formed on some metals by the action of water and air: pipes covered with rust * rust spots * a rust-coloured dress seealsoRUSTY 2 a plant disease that causes reddish-brown spots; the FUNGUS that causes this disease verb if metal rusts or sth rusts it, it becomes covered with rust: [V] old rusting farming implements * Brass doesn't rust. * The floor of the car had rusted through. * [VN] Water had got in and rusted the engine. rusted adjective: rusted iron seealsoRUSTY PHRASALVERBS rust away to be gradually destroyed by rust: There was an old bike rusting away outside.