"Civilization" was coined only a few hundred years ago.
The "very root" was civis, a townsmen or person in a community of any size; and in Rome a city was urbs. The designation was a matter of an individual's legal status, not the size of the town or its complexity. The term predates the founding of Rome.*
Anyway -- speaking of roots, cities are the fruit, not the tree. They don't pop into existence ex nihilo.
So no, not synonymous.
*See The Ancient City, by Fustel de Coulanges.
The existence of a civilization requires the existence of cities. Prior to that, ya got culture. Culture is before, during, and after (or just without) civilization. I have no idea why this has turned into such a problem around here.