Wiktionary
steely-nerved
a. (context idiomatic English) Having a hard, strong, and determined mindset / mentality. Very steady nerves; great patience and courage.
Usage examples of "steely-nerved".
Starting with a prison meeting with Raintree, the steely-nerved writer follows a twisted path that leads to Natalie's parents, to a coincidence that doesn't quite gel, and to a place she has resisted all her life: the dark recesses of her own soul, where she hides the secrets of her own lost past.