>Understood by few; mysterious or secret.
A few words in English with similar meanings are
Esoteric Which broadly means requiring or exhibiting knowledge that is restricted to a small group or difficult to understand or something which belong or understood to/by a small group
Abstruse Difficult to comprehend
He was the only person who understood all the arcane details of the agreement.
This argument may seem arcane to those not closely involved in the world of finance.
Abstruse formule used in organic chemistry
Eric made an esoteric joke that only he and his brother understood.