1. Having a rigidly erect posture, often as a result of feeling angry. Todd stood before me, steely-spined and scowling, arms folded across his chest, and I knew the conversation was over.
2. Determined and resolved. You'll never be able to talk Louise out of this—she's as steely-spined as they come.
3. Calm and unflappable under pressure. I asked my brother to come to court with me because he is always steely-spined in stressful situations. Gina needs to be steely-spined to deal with all the rejection that comes with being an actress.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.