Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. mētrŏpŏlītānus, a, um, adj. [1. metropolis], of or belonging to a metropolis, metropolitan (post-class.): nomen, Cod. Just. 11, 21, 1.
Esp. subst.: Mētrŏ-pŏlītānus, i, m., a metropolitan, the bishop of a metropolitan church, Sid. Ep. 7, 9.
2. Mētrŏpŏlītānus, a, um, adj. [2. Metropolis], of or belonging to the city of Metropolis: campus, Liv. 38, 15.