aerugo

noun

ae·​ru·​go

ēˈ-rü-(ˌ)gō,

i-,

ī-

plural -s

: the rust of a metal and especially brass or copper : verdigris

Word History

Etymology

Middle English erugo "mildew, plant rust," borrowed from Medieval Latin, going back to Latin aerūgō "verdigris," from aer-, aes "bronze, brass, copper" + -ūgō, suffix marking a surface layer or discoloration

First Known Use

1664, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!