n.the date on which an event occurred in some previous year (or the celebration of it)

同義詞：day of remembrance

Anniversaries in mental illness.
Anniversaries, Goodbyes, and Poisons-Life Goes On.
Anniversaries, peroxisomes and reactive oxygen species
Important poultry production anniversaries in 2006
BMJ bans anniversaries. We promise our readers no more boring anniversaries
Classic Maya Mortuary Anniversaries at Piedras Negras, Guatemala
Citation records and some forgotten anniversaries in thermal analysis
Depressive and psychotic states as anniversaries to sibling death in childhood.
The prominent absence of Alfred Russel Wallace at the Darwin anniversaries in Germany in 1909, 1959 and 2009
Review of Atmospheric Chemistry and Environment Research Work in Recent 30 Years——In Commemoration of the 50 Anniversaries of CAMS...