Arcanum
Part of speech: noun
Definition: A mystery or deep secret. An elixir or secret remedy.
Secret
Part of speech: noun
Definition: Knowledge that is hidden and intended to be kept hidden.
Part of speech: verb
Definition: To make or keep secret.
Part of speech: adjective
Definition: Being or kept hidden.
Example sentence: I'm always asked, 'What's the secret to success?' But there are no secrets. Be humble. Be hungry. And always be the hardest worker in the room.