The definition for avian is "Relating to birds." Used in a sentence: The old man affectionately referred to pigeons as his "avian friends."

The definition for buffoonery is "Foolish behavior." Used in a sentence: Clarence, an irrepressible comic, was held after cass for his buffoonery.

The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer.

The definition for disconcert is "To throw into confusion." Used in a sentence: Jennifer's outspoken criticism of the meal disoncerted the waiter.

The definition for incisive is "Impressively direct and decisive." Used in a sentence: Samir's incisive leadership made him the natural choice for president of the company.