Main Entry: her·met·ic

Pronunciation: \(ˌ)hər-ˈme-tik\

Variant(s): also her·met·i·cal \-ti-kəl\

Function: adjective

Etymology: Medieval Latin hermeticus, from Hermet-, Hermes Trismegistus

Date: 1605

1 often capitalized a : of or relating to the Gnostic 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 [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>

— her·met·i·cal·ly \-ti-k(ə-)lē\ adverb