‖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. [ 1913 Webster ]

Inquiries into the arcana of the Godhead. Warburton. [ 1913 Webster ]

2. (Med.) A secret remedy; an elixir. Dunglison. [ 1913 Webster ]