Emily Dickinson Lexicon

STEEL, n. [Sax. style; D. staal; G. stahl; Dan. staal; Sw. stål; probably from setting, fixing, hardness; G. stellen.]

1. Iron combined with a small but definite portion of carbon. It is called in chimistry, carburet of iron. It is used in making instruments, and particularly useful as the material of edged tools. Dr. Thomas Thomson considers that steel is most probably composed of 20 equivalents of iron, and 1 equivalent of carbon. After relaxing, steel strengthens the solids. – Arbuthnot.
2. Figuratively, weapons; particularly, offensive weapon; swords, spears and the like. Brave Macbeth with his brandish'd steel. – Shak. While doubting thus he stood, / Receiv'd the steel bath'd in his brother's blood. – Dryden.
3. Extreme hardness; as, heads or hearts of steel.