hermetic
🇺🇸
/hɜːrˈmetɪk/
🇬🇧
/hɜːˈmetɪk/
Completely sealed so no air or anything else can get in or out.
The container was hermetic, keeping the precious contents safe.
Very private and not open to outsiders.
She lived in a hermetic community, rarely interacting with the outside world.