Esoteric and Orphic

Esoteric adjective - Difficult for one of ordinary knowledge or intelligence to understand.

Orphic and esoteric are semantically related in mysterious topic. In some cases you can use "Orphic" instead an adjective "Esoteric".

Orphic adjective - Having an import not apparent to the senses nor obvious to the intelligence; beyond ordinary understanding.

Esoteric and orphic are semantically related in abstract topic. You can use "Esoteric" instead an adjective "Orphic", if it concerns topics such as intellectual, mysterious, occult, out-of-the-way.