esoteric

Esoteric refers to knowledge, information, or activities that are intended for or understood by only a small number of people with a specialized interest or expertise. Imagine a secret society meeting in a hidden library, discussing topics that the average person would find completely baffling or inaccessible. It is typically used to describe things that are obscure, highly technical, or mystical. While it can imply a sense of intellectual superiority, it is also used neutrally to describe niche academic subjects, such as "esoteric philosophy" or "esoteric computer programming languages."
In conversation
Discussing a niche hobby
I started reading these ancient manuals on clockwork mechanics.
I started reading these ancient manuals on clockwork mechanics.
That sounds pretty esoteric. Where do you even find those?
That sounds pretty esoteric. Where do you even find those?
Used to describe a highly specialized and obscure interest.
Commenting on a complex lecture
Did you understand any of that professor's lecture?
Did you understand any of that professor's lecture?
Not at all. It was far too esoteric for me; I think he was speaking to the two experts in the front row.
Not at all. It was far too esoteric for me; I think he was speaking to the two experts in the front row.
Used to describe information that is inaccessible to the general public.
Examples
The professor studied esoteric rituals of the ancient world.
The professor studied esoteric rituals of the ancient world.
He has an esoteric knowledge of rare 19th-century postage stamps.
He has an esoteric knowledge of rare 19th-century postage stamps.
The software's documentation was so esoteric that only the original developers could navigate it.
The software's documentation was so esoteric that only the original developers could navigate it.