an extraordinary or unusual thing, person, or event; an exceptional example or instance.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
a stew of meat, vegetables, potatoes, etc.
an extraordinary or unusual thing, person, or event; an exceptional example or instance.
"hidden things," 1590s, a direct adoption from Latin of plural of arcanum, from L. neut. of adj. arcanus "secret, hidden" (see arcane). Occasionally mistaken for a singular and pluralized as arcanas since arcana is far more common than arcanum.