Temerarious

[…] he furthwith by thinſtinct of yͤ ſpirite of god, in repꝛoche of all ſuch temerarious bold & blind iudgement, geuē vpon a mā whoſe inward mind and ſodain change they cannot ſee, ſhoꝛtly proued thē al deceiued, […]

Source: wiktionary

To look back upon the past year, and see how little we have striven and to what small purpose; and how often we have been cowardly and hung back, or temerarious and rushed unwisely in; and how every day and all day long we have transgressed the law of kindness;—it may seem a paradox, but in the bitterness of these discoveries, a certain consolation resides.

Source: wiktionary

It was a very bright, hot winter's day, and try as I might, I could not bring myself to think of any danger. I believe that in this way most temerarious deeds are done; the doer has become insensible to danger, and his imagination is clouded with some engrossing purpose.

Source: wiktionary

With a vicious lunge the elephant swerved to the right to dispose of this temerarious foeman who dared intervene between himself and his intended victim; but he had not reckoned on the lightning quickness that could galvanize those steel muscles into action so marvelously swift as to baffle even a keener eyesight than Tantor’s.

Source: wiktionary