noun
12th anniversary of one's death
Buddhist memorial service held on the 12th anniversary of a person's death, counting the year of death as the first anniversary.
来月は祖母の十三回忌です。
Next month is the 12th anniversary of my grandmother's death.
Compound of 十三 (thirteen) + 回忌 (anniversary of death). The number thirteen reflects the traditional Japanese counting where the year of death is the first anniversary, making the 12th solar year the 13th memorial year.