esoteric
Intended for or likely to be understood by only a small number of people with a specialized knowledge or interest, or an enlightened inner circle.
Example
“The writing in this manual is very esoteric; I’d need a degree in engineering just to understand it!”
Other meanings
Having to do with concepts that are highly theoretical and without obvious practical application; often with mystical or religious connotations.
en-3Confidential; private.
“an esoteric purpose”
Where this comes from
This definition is adapted from “esoteric” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.