What is "poleis"

Usage examples of "poleis".

For centuries afterward large parts of Greece were occupied by these independent poleis, with no overarching political unity, and the development of Greek thought and culture was profoundly influenced by this form of political organization.

Did I think, did I dream, did I imagine, that an Olympian god, scion of Zeus Thunderer, protector of Sparta and Amyklai, guardian of Delphi and Delos and who knows how many other poleis, would piss away his valuable time swooping down to chat in the snow with a cityless heliokekaumenos like me?