hermetic

(hər-mĕtˈĭk) also her·met·i·cal (-ĭ-kəl)

1. Completely sealed, especially against the escape or entry of air.
2. Impervious to outside interference or influence: the hermetic confines of an isolated life.
3. often Hermetic
   a. Mythology Of or relating to Hermes Trismegistus or the works ascribed to him.
   b. Having to do with the occult sciences, especially alchemy; magical.

Related Forms:

• her·metˈi·cal·ly adverb