Try Our Apps


Avoid these words. Seriously.


[slag] /slæg/
Also called cinder. the more or less completely fused and vitrified matter separated during the reduction of a metal from its ore.
the scoria from a volcano.
waste left over after the re-sorting of coal.
verb (used with object), slagged, slagging.
to convert into slag.
Metallurgy. to remove slag from (a steel bath).
verb (used without object), slagged, slagging.
to form slag; become a slaglike mass.
Origin of slag1
1545-55; < Middle Low German slagge; cognate with German Schlacke dross, slag; see slack2
Related forms
slagable, adjective
slagability, noun
slagless, adjective
slaglessness, noun
unslagged, adjective


[slag] /slæg/
British Slang. an abusive woman.
First recorded in 1780-90; originally an argot word for a worthless person or a thug; perhaps identical with slag1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for slag
Contemporary Examples
Historical Examples
  • The separation of the slag and iron is facilitated by throwing in some lime from time to time.

  • Of these, oyster or marine shells, burnt shale, and slag are most common.

  • Because, at the foot of the tree, as if broken off the stone, fragments of slag were found.

    The Book of the Damned Charles Fort
  • This cement is made of limestone and clay, or marl, chalk, and slag.

    Diggers in the Earth Eva March Tappan
  • slag and sand were delivered to the mixer by means of wheelbarrows.

    Concrete Construction Halbert P. Gillette
  • slag, being a man of feeling, opined that it was absence of mind.

    The Coxswain's Bride R.M. Ballantyne
  • Now the surface was a lethal desert of slag and rolling clouds.

    The Defenders Philip K. Dick
British Dictionary definitions for slag


Also called cinder. the fused material formed during the smelting or refining of metals by combining the flux with gangue, impurities in the metal, etc. It usually consists of a mixture of silicates with calcium, phosphorus, sulphur, etc See also basic slag
a mass of rough fragments of pyroclastic rock and cinders derived from a volcanic eruption; scoria
a mixture of shale, clay, coal dust, and other mineral waste produced during coal mining
(Brit, slang) a coarse or dissipated girl or woman
verb slags, slagging, slagged
(transitive) (Brit, slang) (usually foll by off) to abuse (someone) verbally
(intransitive) (Austral, slang) to spit
Derived Forms
slagging, noun
slaggy, adjective
Word Origin
C16: from Middle Low German slagge, perhaps from slagen to slay
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for slag

"refuse from smelting," 1550s, from Middle Low German slagge (German Schlacke) "splinter flying off when metal is struck," related to Old High German slahan "to strike, slay" (see slay (v.)).


"denigrate," by 1971, from slag (n.) in a secondary sense of "worthless person" (1788). Related: Slagged; slagging.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
slag in Science
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.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Slang definitions & phrases for slag



: its purposeful indie-rock slag at commerciality


(also slag off) To denigrate; bad-mouth, put down: Everybody was getting slagged/ I don't mean to slag the girls at Douglas/ This time I can't give it to you, can't totally slag you off (1971+)

[origin unknown; perhaps fr German schlagen, ''beat, whip'']

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
Cite This Source

Word of the Day

Nearby words for slag

Difficulty index for slag

All English speakers likely know this word

Word Value for slag

Scrabble Words With Friends