Wiktionary
steely-eyed
a. 1 (context idiomatic English) Having a hard, strong, and determined look about oneself. 2 (context idiomatic English) Having a hard, strong, and determined mindset / mentality.
Usage examples of "steely-eyed".
Kinsman is certainly not the stereotypical steely-eyed, jut-jawed hero of adventure fiction, nor is he much like the public image of NASA's astronauts.
Murphy was going to send a tropical depression into their midst on the days they were scheduled to battle the steely-eyed LieuÂ.
Murphy was going to send a tropical depression into their midst on the days they were scheduled to battle the steely-eyed Lieutenant William Hawken and his merry band of mock terrorists.