adjective her·met·ic \(ˌ)hər-ˈme-tik\
variants: or less commonly


play \(ˌ)hər-ˈme-ti-kəl\

Definition of hermetic

  1. 1 often capitalized a :  of or relating to the mystical and alchemical writings or teachings arising in the first three centuries a.d. and attributed to Hermes Trismegistusb :  relating to or characterized by subjects that are mysterious and difficult to understand :  relating to or characterized by occultism or abstruseness :  recondite a hermetic discussion

  2. 2 [from the belief that Hermes Trismegistus invented a magic seal to keep vessels airtight] a :  airtight hermetic sealb :  impervious to external influence trapped inside the hermetic military machine — Jack Newfieldc :  recluse, solitary leads a hermetic life


play \(ˌ)hər-ˈme-ti-k(ə-)lē\ adverb

hermetic was our Word of the Day on 06/24/2016. Hear the podcast!

Examples of hermetic in a Sentence

  1. wrote hermetic poetry whose sole intended readership was himself

hermetic Has Origins in Greek Mythology

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."

Origin and Etymology of hermetic

Medieval Latin hermeticus, from Hermet-, Hermes Trismegistus

Other Religion (Eastern and Other) Terms

HERMETIC Defined for English Language Learners



Definition of hermetic for English Language Learners

  • : closed tightly so that no air can go in or out

Medical Dictionary


adjective her·met·ic \(ˌ)hər-ˈmet-ik\

Medical Definition of hermetic

  1. :  being airtight or impervious to air


\-i-k(ə-)lē\play adverb

Biographical Note for hermetic

Hermes Trismegistus

\ˈhər-(ˌ)mēz-ˌtris-mə-ˈjis-təs\play , Greek mythological character. Hermes Trismegistus was identified by the Greeks with the Egyptian god Thoth. To him was ascribed authorship of various works on astrology, magic, alchemy, and medicine. It was also believed that he had invented a magic seal to keep vessels airtight, and from his name the adjective hermetic meaning airtight was derived.

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the weight of a container

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