This is the 8679th most frequent Korean word.
가족회사다
It means "to be a family-run company."
The term '가족회사다' indicates that the company is operated or owned by family members.
이 회사는 가족회사다.
This company is a family-run business.
Here '가족회사다' describes the nature of the business he is engaged in.
그는 오랫동안 가족회사다.
He has been part of a family-run business for a long time.
In this sentence, '가족회사다' refers to the kind or type of business they are intending to establish.