[slag] 
noun, verb, slagged, slag⋅ging.| 1. | Also called cinder. the more or less completely fused and vitrified matter separated during the reduction of a metal from its ore. |
| 2. | the scoria from a volcano. |
| 3. | waste left over after the re-sorting of coal. |
| 4. | to convert into slag. |
| 5. | Metallurgy. to remove slag from (a steel bath). |
| 6. | to form slag; become a slaglike mass. |
| slag (slāg) Pronunciation Key
The vitreous mass left as a residue by the smelting of metallic ore. It consists mostly of the siliceous and aluminous impurities from the iron ore. |
