rite of passage

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A ritual or ceremony signifying an event in a person's life indicative of a transition from one stage to another, as from adolescence to adulthood.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anthropology a ceremony or series of ceremonies, often very ritualized, to celebrate a transition in a person’s life. Baptisms, bar mitzvahs, weddings and funerals are among the best known examples.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a ritual performed in some cultures at times when an individual changes status (as from adolescence to adulthood)