Late Middle English (denoting the see of a metropolitan bishop): via late Latin from Greek mētropolis 'mother state', from mētēr, mētr- 'mother' + polis 'city'.

• police from Late Middle English:

  In the 15th century police, which came from medieval Latin politia ‘citizenship, government’, was another word for policy, from the same source. Over time the word came to mean ‘civil administration’ and then ‘maintenance of public order’. The first people to be called police in the current sense was the Marine Police, a force set up around 1798 to protect merchant shipping in the Port of London. The police force established for London in 1829 was for some time known as the New Police. See also constable, copper. Latin politia had been borrowed from Greek polis ‘city, state’, also found in metropolis (Late Middle English) ‘mother city’ in Greek; acropolis (mid 17th century)‘high city’; cosmopolitan (mid 17th century) from kosmos, ‘world’; and politics. We have the ancient Greek philosopher Aristotle to thank for politics. Aristotle, a pupil of Plato and tutor to Alexander the Great, wrote a treatise called ta politika, or ‘The Affairs of State’, which gave us our word. The concept of political correctness originated in the USA during the 1980s but the expression dates back a lot longer. It is recorded in 1840 in the USA, and politically correct goes back even further, to 1793, in the records of the US Supreme Court. Originally both terms referred to people conforming to the prevailing political views of the time.