shutdown

From the verb phrase shut down.

shutdown (plural shutdowns)

1. The action of stopping operations; a closing, of a computer, business, event, etc.

   You need to enter your password at startup, but it's not required at shutdown.

2. A statement, insult, etc. that prevents the opponent from replying further.

   When he insulted me, my reply was such a shutdown that he left the room.

3. An autistic response to stress, etc. where the individual becomes silent and motionless.

• startup

• shut down