quintessential

adjective
1

Of the nature of a quintessence (in all senses); being or relating to the ultimate essence of something.

noun
1

The fundamental essence of something.

Source: https://en.wiktionary.org/wiki/quintessential

Definitions come from the Free Dictionary API (dictionaryapi.dev), with Wiktionary as a fallback when it is slow, and are cached for up to 24 hours.