Wiktionary
zone out
vb. (context intransitive English) To stop paying attention and think about something else, or to think about nothing
Usage examples of "zone out".
Kuwait and Saudi Arabia continue to support the NFZs only because the southern zone provides vital warning of an Iraqi attack, and Turkey puts up with the northern zone out of deference to its American allies and fear that Washington would retaliate regarding other key Turkish interests (Cyprus, its application for European Union membership, and so on) if it did not.
Whenever I started to push at getting released, my dosage would be upped and I'd truly zone out for awhile.
We're still in a dark zone out there till all the sat-repeaters are put back in place.