Adjective

(en adjective)

Making arbitrary decisions, especially in an impulsive and forceful manner.

* 1880 , John Weeks Moore, Complete Encyclopaedia of Music , "":

But it was natural, that the impetuous , restless young artist should incline more to excess of strength than of delicacy in his playing.

Characterized by sudden and violent force.

* 1794 , :

He stands, and views in the faint rays
Far, far below, the torrent's rising surge,
And listens to the wild impetuous roar

Adjective

(er)

Very bad or intense.

* {{quote-magazine, date=2012-01

, author=Donald Worster , title=A Drier and Hotter Future , volume=100, issue=1, page=70 , magazine= citation , passage=Phoenix and Lubbock are both caught in severe drought, and it is going to get much worse. We may see many such [dust] storms in the decades ahead, along with species extinctions, radical disturbance of ecosystems, and intensified social conflict over land and water. Welcome to the Anthropocene, the epoch when humans have become a major geological and climatic force.}}

Strict or harsh.

Sober, plain in appearance, austere.