[spee-guh
l-ahy-zuhn] 
| a lustrous, crystalline pig iron containing a large amount of manganese, sometimes 15 percent or more, used in making steel. |
| spie·gel·ei·sen (spē'gə-lī'zən) n. An alloy of iron containing approximately 15 percent manganese and small quantities of carbon and silicon, used in the Bessemer process. [German : Spiegel, mirror (from Middle High German, from Old High German spiagal, from Latin speculum; see speculum) + Eisen, iron (from Middle High German īsen, from Old High German īsan; see eis- in Indo-European roots).] |