Which word is similar to 'Esoteric'?

Esoteric (adjective):
English Meaning: Intended for or understood by only a few people who have special knowledge.
Bangla Meaning: কেবল দীক্ষিত ব্যক্তিরা বুঝতে পারে এমন দুর্বোধ্য।

• Synonyms: Abstruse (দুর্বোধ্য; গূঢ়; নিগূঢ়), Perplexing (হতবুদ্ধিকর), Complex (জটিল; যৌগিক; দুর্বোধ্য), Cryptic (রহস্যময়), Bewildering (বিভ্রান্তিকর)। 
• Antonyms: Simple (নির্ঝঞ্ঝাট), Familiar (পরিচিত; চেনাজানা), Easy (সহজ) Common (সাধারণ), Obvious (সহজেই বোধগম্য এমন)।

Other Forms: Esoterically (adverb).

Example Sentence: 
1. Literary readings can sometimes seem esoteric, but we are trying to make them more attractive to more people.
2. I was amazed by seeing his collection of esoteric philosophical theories.

Other options, 
Dissociated - বিচ্ছিন্ন;
Offense - অপরাধ। 

Source: Lecture.