/herr met"ik/ , adj.
1. made airtight by fusion or sealing.
2. not affected by outward influence or power; isolated.
3. ( sometimes cap. ) of, pertaining to, or characteristic of occult science, esp. alchemy.
4. ( cap. ) of or pertaining to Hermes Trismegistus or the writings ascribed to him.
Also, hermetical .
[ 1630-40; hermeticus of, pertaining to Hermes Trismegistus, equiv. to L Herme ( s ) HERMES + -ticus -TIC ]