Original: The word originates from the ancient Greek city-states, which developed during the Archaic period, the ancestor of city, state and citizenship, and persisted (though with decreasing influence) well into Roman times, when the equivalent Latin word was civitas, also meaning 'citizenhood', while municipium applied to a non-sovereign local entity.
Simplified: The word originates from the ancient Greek city-states, which developed during the Archaic period and existed well into Roman times, when the equivalent Latin word was civitas, that means 'citizenhood' as well.