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adjective her·met·ic \(ˌ)hər-ˈme-tik\

Simple Definition of hermetic

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

Source: Merriam-Webster's Learner's Dictionary

Full 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 Trismegistus b :  relating to or characterized by occultism or abstruseness :  recondite

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

hermetically play \-ti-k(ə-)lē\ adverb

Examples of hermetic in a sentence

  1. <wrote hermetic poetry whose sole intended readership was himself>

Did You Know?

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 "recluse" or "solitary."

Variants of hermetic

also hermetical play \-ti-kəl\

Origin of hermetic

Medieval Latin hermeticus, from Hermet-, Hermes Trismegistus

First Known Use: 1605

Other Religion (Eastern and Other) Terms

Medical Dictionary


adjective her·met·ic \(ˌ)hər-ˈmet-ik\

Medical Definition of hermetic

  1. :  being airtight or impervious to air

hermetically \-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.

Seen and Heard

What made you want to look up hermetic? Please tell us where you read or heard it (including the quote, if possible).


to expose to danger or risk

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