This is the 750th most frequent Japanese word.
追悼
Mourning or memorial tribute.
In this sentence, '追悼' refers to the act of mourning or showing respect for someone who has passed away.
彼らは亡くなった友人を追悼しました。
They commemorated their deceased friend.
Here, '追悼' is used to indicate a memorial event meant to honor those who lost their lives in a disaster.
災害追悼式が来週行われる予定です。
The disaster memorial ceremony is scheduled to take place next week.
In this context, '追悼' expresses showing respect and remembrance for the deceased.