1. The scum formed by oxidation at the surface of molten metals
   "slag was removed from the surface of the molten iron";
   - scoria, dross
    
2. Stony waste matter, or material of similar appearance
   "a slag heap"
    
3. [Brit, offensive] A promiscuous woman
   "He rudely referred to his ex-girlfriend as a slag";

1. Convert into slag
   "The intense heat slagged the impurities in the metal"
    
2. [Brit, vulgar] Criticize, insult, talk down
   "He's always slagging off his coworkers behind their backs";

Derived forms: slagged, slagging, slags

Type of: convert, scum

Encyclopedia: Slag