| 1. | made airtight by fusion or sealing. |
| 2. | not affected by outward influence or power; isolated. |
| 3. | (sometimes initial capital letter ) of, pertaining to, or characteristic of occult science, esp. alchemy. |
| 4. | (initial capital letter ) of or pertaining to Hermes Trismegistus or the writings ascribed to him. |
hermetic her·met·ic (hər-mět'ĭk) or her·met·i·cal (-ĭ-kəl)
adj.
Completely sealed, especially against the escape or entry of air.