impetuosity

The quality of making rash or arbitrary decisions, especially in an impulsive or forceful manner.

She had however another motive, beside her obedience, to accompany the old gentleman in the chase; for by her presence she hoped in some measure to restrain his impetuosity, and to prevent him from so frequently exposing his neck to the utmost hazard.

The condition or quality of being impetuous, impatient; fury; violence.

Again his lordship began his long and deliberate perusal, while Henrietta watched the slow motion of his eyes with a degree of impetuosity she could scarcely repress.