Definitions

1. adjective

of or relating to alchemy or hermetic philosophy, especially in its 16th-century Italian form

“The alchemist’s manuscript described an elaborate system of hermetic symbols.”

2. noun

a person who practices hermetic philosophy or alchemy

“The hermeticist spent years studying the ancient art of transmutation.”

3. noun

something (such as a seal or a container) that is airtight and impervious to air or gas

“The hermetic seal on the container prevented any air from entering.”

4. adjective

sealing tightly so as to be impervious to air or gas; airtight

“The engineer designed a hermetic compartment to maintain a consistent atmosphere.”