hermeticyoudaoicibaDictYouDict[hermetic 词源字典]
hermetic: [17] Hermetic means literally ‘of Hermes’. Not Hermes the messenger of the Greek gods, though, but an Egyptian priest of the time of Moses, who in the Middle Ages was regarded as identical with the versatile Hermes in his capacity of patron of science and invention, and who was thus named Hermes Trismegistus ‘Hermes the thrice greatest’. This shadowy figure was the supposed author of various works on alchemy and magic, and so the term hermetic came to be roughly synonymous with alchemical.

One of the inventions credited to Hermes Trismegistus was a magic seal to make containers airtight, and by the 1660s we find hermetic being used for ‘airtight’.
[hermetic etymology, hermetic origin, 英语词源]
hermetic (adj.)youdaoicibaDictYouDict
c. 1600 (implied in hermetically), "completely sealed," also (1630s) "dealing with occult science or alchemy," from Latin hermeticus, from Greek Hermes, god of science and art, among other things, identified by Neoplatonists, mystics, and alchemists with the Egyptian god Thoth as Hermes Trismegistos "Thrice-Great Hermes," who supposedly invented the process of making a glass tube airtight (a process in alchemy) using a secret seal.