An Athenian is a person from Athens, the capital of Greece. As an adjective it means “of Athens” or “like Athens”: Athenian art, Athenian democracy, an Athenian street. Ancient Athens was the most important city of old Greece, and people still travel there to see the old monuments, especially the Acropolis — so Athenian can point to today’s city or to that old world of plays, philosophy, and city votes. It takes a capital letter when it means the place or its people, like other city words of this kind. Though actually, the word is not the city name. Athens is the place; Athenian is the person, or the “of-that-place” word — the same pattern as Rome / Roman.