Sprezzatura

Italian, a rich language, has many interesting words with great historical heritage.
For example the word sprezzatura was coined by Baldassarre Castiglione, a Renaissance man.
He was a diplomat, soldier, writer and play producer.
An eclectic man like most Renaissance Italian scholars.

In his book Libro del Cortegiano (which could be translated roughly as Book of the Gentleman) he gives the following definition

e, per dir forse una nova parola, usar in ogni cosa una certa sprezzatura, che nasconda l’arte e dimostri ciò che si fa e dice venir fatto senza fatica e quasi senza pensarvi.

Which could be translated as

and, coining probably a new term, (a gentleman?) should use a certain degree of sprezzatura, so as to hide his proficiency and to show his deeds as done without effort and almost without any thinking.

Thanks Professor Ritson for pointing this word to me.