Of, pertaining to, or taught by, Hermes Trismegistus; as, hermetic philosophy. Hence: Alchemical; chemic.

Of or pertaining to the system which explains the causes of diseases and the operations of medicine on the principles of the hermetic philosophy, and which made much use, as a remedy, of an alkali and an acid; as, hermetic medicine.

Secret, occult; especially the Western mystery tradition.

Made perfectly close or air-tight by fusion, so that no gas or spirit can enter or escape; as, an hermetic seal. See Note under Hermetically.

Refers to a device that is sealed by either metal to metal or glass to metal fusion to prevent moisture or contaminants from entering the switch cavity. The degree of seal is numerically expressed in the form of a maximum allowable leak rate. Example: 1 x 10-8 ATM cc/s

An airtight sealed system.