patina (n.) Look up patina at Dictionary.com
"greenish film on old bronze," 1748, from French patine (18c.), from Italian patina, perhaps from Latin patina "shallow pan, dish, stew-pan," from Greek patane "plate, dish," from PIE *pet-ano-, from root *pete- "to spread." The ancient notion is of encrustation on bronze plates and pans. Sense of "refinement, cultural sophistication" first recorded 1933.