घनिष्ठ रूप से जुड़ा हुआ  =  closely attached
He knew about the robbery, but wasn't directly/actively/personally involved.

घनिष्ठ रूप से सम्बद्ध  =  closely connected
He sees her often but doesn't want to get too involved.

जटिल  =  complicated
An involved sentence.

अंतर्ग्रस्त
Information on the airlines or countries involved in the hijacking

पेचीदा
The plot was too involved.