inauguration

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

• noun Formal induction into office.
• noun A formal beginning or introduction.

from The Century Dictionary.

• noun The act of inaugurating or inducting into office with solemnity; ceremonial investiture with office.
• noun The act of solemnly or formally introducing or setting in motion anything of importance or dignity; a definite beginning or initiation: as, the inauguration of a new era or a new system.
• noun A ceremonial or formal introduction or opening, as of something intended for public use: as, the inauguration of a monument or an exhibition.

from the GNU version of the Collaborative International Dictionary of English.

• noun The act of inuagurating, or inducting into office with solemnity; investiture by appropriate ceremonies.
• noun The formal beginning or initiation of any movement, course of action, etc.

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

• noun The act of inaugurating, or inducting into office with solemnity; investiture by appropriate ceremonies.
• noun The formal beginning or initiation of any movement, course of action, etc.; as, the inauguration of a new system, a new condition, etc.

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

• noun the ceremonial induction into a position
• noun the act of starting a new operation or practice