7 letters · 10 points in Scrabble
noun discoloration of metal surface caused by oxidation
verb make dirty or spotty, as by exposure to air; also used metaphorically
originFrom 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.
Etymology from Wiktionary, CC BY-SA 3.0