Having a hard, strong, and determined look about oneself.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "steely-eyed" in a sentence
"When squad cars near, he parks, his expression steely-eyed calm."
"Stingy, steely-eyed and spectacular, while he walked six, he fanned an equal number; and no other baserunner besides the leadoff batter Ellsbury—who was left stranded in that first inning—reached third."
"I cast a glance in Hazel's direction—she gives me the steely-eyed gaze that has caused so many budding young aethetes to realize there's room for only one poetess in our town, and Hazel's not going anywhere."