verb

1. To close, terminate, or end.

   “They are planning to shut down the entire building at the end of the month.”

2. To turn off or stop.

   “It's a good idea to shut down the machine before you leave.”

3. To emotionally withdraw into oneself as a defense mechanism; to block out external stressors.

   “I can't talk to him about a certain thing; he just shuts down anytime I try.”

Synonyms: close down