tarnish

Definition

Oxidation or discoloration, especially of a decorative metal exposed to air.

Etymology

From Middle English ternysshen, from Old French terniss-, stem of ternir (“to make dim, make wan”), borrowed from Old High German *ternen, tarnen, from Proto-West Germanic *darnijan (“to conceal”). Doublet of dern and darn.

Example Sentences

• "1918, Hannah Teresa Rowley, Mrs. Helen Louise (Wales) Farrell, Principles of Chemistry Applied to the Household Precipitated calcium carbonate, a very fine powdery form, is used as a basis for many tooth powders and pastes. As whiting it finds a wide use in cleaning metals of their tarnishes."
• "Limiting the use of silver to special occasions might invite tarnish unless the pieces are carefully protected."