the day or the anniversary of the day of a person's death.
Origin of deathday
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for deathday
Historical Examples of deathday
Who crowns his bust with laurels, or celebrates his birthday and his deathday with solemn festivals and pompous panegyrics?Renaissance in Italy, Volume 2 (of 7)
John Addington Symonds