adj. 25B6; adjective ABSTRUSE, obscure, arcane, recherché, rarefied, recondite, abstract; enigmatic, inscrutable, cryptic, Delphic; complex, complicated, incomprehensible, opaque, impenetrable, mysterious.
ESOTERIC
Meaning of ESOTERIC in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012