: a date that is remembered or celebrated because a special or notable event occurred on that date in a previous year
Full Definition of ANNIVERSARY
: the annual recurrence of a date marking a notable event; broadly: a date that follows such an event by a specified period of time measured in units other than years <the 6-month anniversary of the accident>
The exhibit will close on the 100th anniversary of the artist's death.
Origin of ANNIVERSARY
Middle English anniversarie, from Medieval Latin anniversarium, from Latin, neuter of anniversarius returning annually, from annus year + versus, past participle of vertere to turn — more at annual, worth