zone out

late 14c., from Latin zona "geographical belt, celestial zone," from Greek zone "a belt," related to zonnynai "to gird," from PIE root *yes- "to gird, girdle" (cf. Avestan yasta- "girt," Lithuanian juosiu "to gird," Old Church Slavonic po-jasu "girdle").

Originally one of the five great divisions of the earth's surface (torrid, temperate, frigid; separated by tropics of Cancer and Capricorn and Arctic and Antarctic circles); meaning "any discrete region" is first recorded 1822. Zone defense in team sports is recorded from 1927. Zoning "land-use planning" is recorded from 1912. Zoned (adj.) in drug-use sense is attested 1960s, from ozone, which is found high in the atmosphere; the related verb to zone is from 1980s.