Definition of slag in English:

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Pronunciation: /slaɡ/


1 [mass noun] Stony waste matter separated from metals during the smelting or refining of ore: the burning liquid iron was forming a scum of slag
More example sentences
  • The hardened matter was slag, a waste product from metal working, and contained evidence of iron, copper and lead manufacture.
  • In highly developed countries, the major components of industrial waste are blast furnace and steel slag, and power station ash.
  • The union has leveled 15 separate charges against Levy, a contractor at Mittal Steel USA, which performs slag processing and metal reclamation.
1.1Stony material ejected by a volcano; scoria: [count noun]: flow after flow of lava, slags, powders, and ejecta cast upon the previous outpourings in grotesque patterns
More example sentences
  • Thirdly, reduce the clinker content in cement, by intergrinding cementious material like slag, fly ash, or limestone.
  • The difference in densities of the molten iron and molten slag allow each material to be removed separately from the furnace.
  • It was a more rustic and northern version of Detroit with escarpments of slag and iron ore.
2British informal, derogatory A promiscuous woman.
Example sentences
  • Boys continued to make the same distinction between prospective wives and slags.
  • If you look beyond the dehumanising stereotypes to the hard facts, it emerges that females in jail are not conniving slags.
  • She told him Trev had called her a dirty slag after their drink the other night and had refused to sleep with her.
2.1A contemptible or insignificant person.
Example sentences
  • I created it especially to deal with nosey slags like you!

verb (slags, slagging, slagged)

1 [no object] (usually as noun slagging) Produce deposits of slag: the furnace burns at a minimum temperature to reduce slagging
2 [with object] British informal Criticize (someone) in an abusive and insulting manner: my girlfriend was always slagging him off
More example sentences
  • When he does those anthologies he gets slagged by the critics but they're the books that sell and support everything else that he does.
  • People slag me off because I'm a larger-than-life character, and that's part of my thing from the past - I lived my life very excessively.
  • Meanwhile, Hain himself can slag people off just because they don't conform to his narrow vision of what constitutes a Brit.



adjective (slaggier, slaggiest)
Example sentences
  • The whole of it waggled with unhealthy cushions of fat; it all hung, it was all slack and without structure - slaggy, gelatinous, sick.
  • Everyone must have some sympathy with Bible Belters and Muslims who point to the slaggy decadence of secular western culture.


Mid 16th century: from Middle Low German slagge, perhaps from slagen 'strike', with reference to fragments formed by hammering. The verb sense 'criticize' dates from the 1970s.

  • Slag is from Middle Low German slagge, perhaps from slagen ‘strike’, with reference to fragments formed by hammering. From the sense of refuse developed a slang use meaning ‘worthless person’ in the late 18th century, which only developed the modern dominant sense ‘promiscuous woman’ in the mid 20th century. The verb sense ‘criticize’ as in slagged off, dates from the 1970s.

Words that rhyme with slag

bag, blag, brag, Bragg, crag, dag, drag, flag, gag, hag, jag, lag, mag, nag, quag, rag, sag, scrag, snag, sprag, stag, swag, tag, wag, zag

For editors and proofreaders

Line breaks: slag

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