Used by arrangement with John Wiley & Sons, Inc.
noun pl. ar·ca·na or ar·ca·nums
- A deep secret; a mystery.
- often arcana Specialized knowledge or detail that is mysterious to the average person: “knows the arcana of police procedure and the intricacies of litigation” (George F. Will).
- A secret essence or remedy; an elixir.
Origin: Latin arcānum, from neuter of arcānus, secret; see arcane.