Aplomb

Noun.

Complete and confident self composure or self assurance: poise.

[Origin: French, literally, perpendicularity, from Middle French, from a plomb, literally, according to the plummet.]

(1823)

“There are one or two artists, but I have noted that there is only a slight correlation between a taste for history and practising the arts. And over the last twelve years, you might say I’ve got to know all of them. And all of them, whoever they are, are won over by the costumes, the faithful reproduction of official texts, the period atmosphere, and, I think I may say, the fact of wearing an eighteenth-century frock coat. It lends one aplomb. – A Climate of Fear, Fred Vargas.