Vaticanian adjective 1noun 1forms 1 adjective1 •(literary) Relating to the Vatican (any sense); (figuratively) papal.The pope of Rome, when all remonstrance fail’d, / As the last act of his supremacy / Commission’d Legates to assuage the feud, / Or threat the king with Vaticanian wrath. — 1843 noun1 •(informal) A person from Vatican City. formsVaticanians