[ad_1] noun, plural ar·ca·na [ahr-key-nuh] /ɑrˈkeɪ nə/.
- Often arcana. a secret; mystery.
- a supposed great secret of nature that the alchemists sought to discover.
- a secret and powerful remedy.
- secret of secrets.
noun plural -na (-nə)
- (sometimes plural) a profound secret or mystery known only to initiates
- a secret of nature sought by alchemists
proper singular form of.