na-adjective
insular; closed; exclusive; unsociable
Describes a group, organization, or person that is closed off to outsiders, resistant to new ideas, or unapproachable. Often carries a negative connotation.
Antonyms: 開放的
あの会社は閉鎖的で、新しい意見を受け入れない。
That company is insular and doesn't accept new ideas.
彼は閉鎖的な性格で、なかなか友達ができない。
He has an unsociable personality and has trouble making friends.