Temerarious

(a.) Unreasonably adventurous; despising danger; rash; headstrong; audacious; reckless; heedless.

Thesaurus Entries

adventurous, aggressive, ambitious, audacious, daredevil, daring, driving, dynamic, enterprising, foolhardy, forceful, go-ahead, hustling, overbold, pushful, pushing, pushy, rash, reckless, temerarious, up-and-coming, venturesome, venturous