galvanized (adj.)

1820, "subject to galvanism," past-participle adjective from galvanize. As "coated with a metal by galvanism" from 1839, originally in galvanized iron.

Iron covered with zinc has been called galvanised iron, from the fact that we have two metals in different electrical conditions; the zinc, suffering chemical change, oxidising, and acting as a protecting agent to the iron. ["Hunt's Hand-Book to the Official Catalogues," 1851]