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

(-)

defective and impossible to materially correct or set aright.

''The construction flaw is incorrigible ; any attempt to amend it would cause a complete collapse.

incurably depraved; not reformable.

''His dark soul was too incorrigible to repent, even at his execution.

impervious to correction by punishment or pain.

''The imp is incorrigible : his bottom is still red from his last spanking when he plans the next prank.

unmanageable.

* {{quote-news

, year=2006 , date=December 7 , author=Michael White , title=Breaking up is hard to do, even at the Treasury , work=the Guardian citation , page= , passage=Gordon Brown may have his grumpy, Granita moments, but as a strategist he is an incorrigible optimist.}}

determined, unalterable, hence impossible to improve upon.

''The laws of nature and mathematics are incorrigible .

(archaic) incurable.