es-oh-TAIR-ik

Definition

(adjective) Intended for or understood by only a small group with specialized knowledge or interest.

Example

The professor’s lecture was so esoteric that even her graduate students struggled to follow the references, let alone the first-year undergraduates in the back row.

Word Origin

Esoteric derives from the Greek esoterikos, meaning “belonging to an inner circle,” from esotero — “inner” — the comparative form of eso, meaning “within.” It was first used to describe the secret teachings of Pythagoras, shared only with his most devoted inner circle of disciples and deliberately withheld from the general public. The word entered English in the 17th century, carrying that same sense of guarded, inner-circle knowledge.