metropolitanism (n.)

early 15c., "belonging to an (ecclesiastical) metropolis," from Late Latin metropolitanus, from Greek metropolites "resident of a city," from metropolis (see metropolitan (n.)). Meaning "residing in or connected with a chief or capital city" is from 1550s. In reference to underground city railways, it is attested from 1867.

word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.