also hermetical adjective
Etymology: Medieval Latin hermeticus, from Hermet-, Hermes Trismegistus
Date: 1605
1. often capitalized of or relating to the Gnostic writings or teachings arising in the first three centuries A.D. and attributed to Hermes Trismegistus, relating to or characterized by occultism or abstruseness ; recondite ,
2. \from the belief that Hermes Trismegistus invented a magic seal to keep vessels airtight] airtight , impervious to external influence , recluse , solitary , hermetically adverb