commemoration

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

• noun The act of honoring the memory of or serving as a memorial to someone or something.
• noun Something that honors or preserves the memory of another.

from The Century Dictionary.

• noun The act of commemorating or calling to remembrance by some solemnity; the act of honoring the memory of some person or event by solemn celebration: as, the feast of the passover among the Israelites was an annual commemoration of their deliverance from Egypt.
• noun Eccles.: In the intercessory prayers of the eucharistic office, mention made by name, rank, or condition of persons living or departed, or of canonized saints; also, a prayer containing such mention: as, the commemoration of the living; the commemoration of the departed; the commemoration of the saints. See diptych.
• noun In the services for the canonical hours, a brief form, consisting of anthem, versicle, response, and collect, said in honor of God, of a saint, or of some biblical or ecclesiastical event: in the medieval church in England also called a memory, and sometimes a memorial. A complete service said in honor of a saint was also so styled.
• noun Parts of the proper service of a lesser festival inserted in the service for a greater festival when the latter coincides with and supersedes the former.

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

• noun The act of commemorating; an observance or celebration designed to honor the memory of some person or event.
• noun Whatever serves the purpose of commemorating; a memorial.
• noun at the University of Oxford, Eng., an annual observance or ceremony in honor of the benefactors of the University, at which time honorary degrees are conferred.

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

• noun The act of commemorating; an observance or celebration designed to honor the memory of some person or event.
• noun Whatever serves the purpose of commemorating; a memorial.

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

• noun a ceremony to honor the memory of someone or something
• noun a recognition of meritorious service