[L. = verdigris; f. æs, æris, brass.] The rust of copper or brass, verdigris; occasionally used for the rust of metals generally.
1753. Chambers, Cycl. Supp., s.v., The ærugo of antient metals adds greatly to their value.
1845. Ford, Handbk. Spain, II. 786. With pumice and emery to scrub off the respectable ærugo.
