Both Uses

impetuous
in
Journey to the Center of the Earth - 44 chapters
(Auto-generated)

It is a matter of great doubt to me now, to what violent measures my uncle's impetuosity might have led him, had not the clock struck two, and our old French cook called out to let us know that dinner was on the table.†
Chpt 1 *

impetuosity = impulsiveness (the trait of acting suddenly without much thought)
"But I see something," I cried, in an impetuous tone of voice, as I rushed forward and eagerly picked up something which shone in the sand under my feet.†
Chpt 37

impetuous = impulsive (acting suddenly without much thought)

Definitions:

(1) (impetuous as in: an impetuous decision)
impulsive (acting suddenly without much thought) -- often with an unfortunate consequence
(2) (meaning too rare to warrant focus)
In historic literature, impetuous often refers to any rapid, forceful, and/or violent movement.