This is the 5220th most frequent Korean word.
단체인
"단체인" means "a member of a group or organization."
Here, '단체인' is used to define and explain the nature of the group as an organization.
이 모임은 지역 주민들이 만든 단체인 것입니다.
This group is an organization created by local residents.
In this sentence, '단체인' is part of the noun being described (organiation's purpose and activities).
우리는 사람들에게 단체인의 목적과 활동을 설명했습니다.
We explained to the people the organization's purpose and activities.
Here, '단체인' is used as an adjective phrase describing the organization to be service-oriented.