This is the 1522nd most frequent Turkish word.
grubun
"Grubun" means "of the group" in English.
In this sentence, "grubun" indicates possession, showing that the leader belongs to the group (genitive case).
Grubun lideri toplantıya katıldı.
The group's leader attended the meeting.
Here, "grubun" shows possession, specifying that the majority is a part of the group.
Grubun çoğunluğu bu fikre katılıyor.
The majority of the group agrees with this opinion.
In this case, "grubun" signifies representation or speaking on the group's behalf, maintaining the genitive case usage.