This is the 5714th most frequent Russian word.
присоединились
"Joined" or "connected."
The word 'присоединились' is used in this sentence to express the action of joining or becoming part of a group actively participating in the procession.
Мы присоединились к праздничной процессии.
We joined the festive procession.
Here, 'присоединились' indicates formally becoming a part of an organized initiative or project.
После долгих переговоров они присоединились к проекту.
After long negotiations, they joined the project.
In this example, 'присоединились' conveys the meaning of participating in a collective action or movement.