Word of the Day:

1 : relating to or characterized by occultism or abstruseness : recondite

2 a : airtight 

b : impervious to external influence

c : recluse, solitary

The infomercial claimed that the new containers used modern technology to guarantee a hermetic seal that would keep food fresh for months.

"Later, as Western Europe welcomed foreign guest workers, Central Europe remained in the hermetic enclosure of Soviet rule." — Sara Miller Llana, The Christian Science Monitor, 10 Mar. 2016

More example sentences

Hermetic derives from Greek via the Medieval Latin word hermeticus. When it first entered English in the early 17th century, hermetic was associated with writings attributed to Thoth, the Egyptian god of wisdom. Thoth, whom the Greeks called Hermes Trismegistus ("thrice-great Hermes"), was believed to be the author of a number of mystical, philosophical, and alchemistic works. The obscure subject matter of these works may have made them difficult to wade through, for soon English speakers were also applying hermetic to things that were beyond ordinary human comprehension. Additionally, Hermes Trismegistus was said to have invented a magic seal that could keep vessels airtight. Hermetic thus came to mean "airtight," both literally and figuratively. These days, it can also sometimes mean "solitary."