‖Ar‐ca″num (�), n.; pl.Arcana (�). [L., fr. arcanus closed, secret, fr. arca chest, box, fr. arcere to inclose. See Ark.] 1. A secret; a mystery; — generally used in the plural.
Inquiries into the arcana of the Godhead.
Warburton.
2. (Med.) A secret remedy; an elixir. Dunglison.