a bluish grey alloy of iron with carbon, notable for its strength and hardness, distinguished from cast iron by its malleability under certain conditions, and widely used in construction work
cold hardness or unyielding strength
nerves of steel
an instrument or implement of steel, e.g.:
a tool, e.g. a ridged rod with a handle, for sharpening knives
a piece of steel for striking sparks from flint
literary a sword or dagger
And as he plucked his cursed steel away, mark how the blood of Caesar follow'd it — Shakespeare
literary a suit of armour
clad in compleat steel — Milton
steel adj
[Old English stẏle, stēle]