This is the 4474th most frequent Russian word.
воссоединение
Reunion.
It refers to the act of reuniting family members, emphasizing the emotional or unexpected context.
Воссоединение семьи было полной неожиданностью.
The family reunion was a complete surprise.
Here, 'воссоединение' is used in a political or territorial context, indicating the joining of divided areas.
Эти исторические события привели к воссоединению двух стран.
These historical events led to the reunification of the two countries.
In this sentence, it implies the coming together of friends, highlighting the personal and celebratory aspect.