Insular or closed-off; not open to outsiders or new ideas—used for people, groups, or organizations.
あの部署は昔から閉鎖的で、外部の意見を取り入れない。
That department has long been closed-off and doesn't incorporate outside opinions.
地域コミュニティが閉鎖的だと、新しい住民がなじめないことがある。
If a local community is closed-off, new residents may have trouble fitting in.
閉鎖的な態度は人間関係の解決を遅らせることがある。
A closed attitude can sometimes delay resolving interpersonal problems.