'hermeticity' originates from the Greek word 'Hermes,' referring to the god associated with magic and alchemy, where 'hermetikos' meant 'sealed or airtight.'

'hermetikos' transformed into the Latin word 'hermeticus,' and eventually became the modern English word 'hermeticity' through Middle English.

Initially, it meant 'sealed or airtight,' and this meaning has largely remained the same in modern usage.