Aerugo

·noun The rust of any metal, ·esp. of brass or copper; verdigris.

aerugo
aerūgo, ĭnis, f. [aes, as ferrugo from ferrum]. I Rust of copper : aes Corinthium in aeruginem incid...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
aerugo
aerūgō inis, f aes, rust of copper, verdigris , C.— Rusty gold , Iu.—Poet., a corroding passion :...

An Elementary Latin Dictionary