HERMETIC

(CLOSED) [adjective] [not gradable] [specialized] - (of a container) so tightly closed that no air can leave or enterThe hermetic seal on the packet means that the food lasts longer.(literary) If a particular society is hermetic, the people who live within it rarely communicate with those who live outside it.He entered the hermetic world of the monastery at a young age.Politics, war and the real world rarely threatened to impinge on her hermetic existence.