<p><strong>Noun</strong></p><ul><li>arcana</li></ul><p><strong>Plural</strong></p><ul><li>arcana</li></ul><p><strong>Definition</strong></p><ul><li>Secret or arcane knowledge, acquired or understood by only a few.</li><li>A supposed great secret of nature that the alchemists sought to discover.</li><li>A secret and powerful remedy; elixir.</li></ul>