arcana

noun

Specialized knowledge that is mysterious to the uninitiated.

The arcana of the ancient civilization remains a mystery.

意味（1）

Specialized knowledge that is mysterious to the uninitiated.

Thou deign'st no answer,—or I fain would ask

If since thy bright creation, thou hast seen

Ought like a Newton, whose admitted eye

The arcana of the universe explored

Light's subtle ray its mechanism disclosed,

The impetuous comet his mysterious lore

Unfolded,