the world > action or operation > doing > activity or occupation > be occupied or busy (in or at something) [verb (intransitive)] > take thought to do or busy oneself (2)
To busy, occupy, or concern oneself closely or earnestly with a subject, etc.; to deal with something as a task or troublesome duty.
intransitive. To struggle mentally; to make a great psychological effort. Chiefly with with: to struggle to cope with or understand something; to…