When the word metropolitan (from the Greekmetera = mother and polis = town) is used as an adjective, as in metropolitan bishop, metropolitan France, or metropolitan area it can mean:
of or belonging to the home territories of a country, as opposed to overseas territories (example: metropolitan France)
of, relating to, or designating an ecclesiastical metropolis (example: metropolitan bishop)
When it is used as a noun, it can mean:
A metropolitan bishop (thus one may write "Alexius became Metropolitan of Kiev in 1354"; including the word bishop in such a sentence would be unusual),