E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Audacious, shameless, impudent. This seems to imply that social and good manners require concealment, or, at any rate, to veil the face with white lies. In Latinretecta facie; in Frenchà visage découvert. Cassius says to his friend Brutus, If I have veiled my looks , that is, concealed my thoughts from you.