Slag

How to spell slag

4 letters · 1 syllable

How to pronounce slag

What does slag mean?

1. nounThe stony waste matter left over when metal ore is smelted or refined.
2. verbTo criticise or insult someone harshly, usually in the phrase 'slag off'.

Slag in a sentence

• noun

  The steelworks dumped tonnes of molten slag into the cooling pit.

• verb

  The pundits never miss a chance to slag off the losing team.

• noun

  Crushed slag from the old furnaces is sometimes used to surface roads.

• verb

  It is unprofessional to slag off a colleague in front of clients.

Where does slag come from?

Language of origin: Germanic

Slag came into English in the sixteenth century from Middle Low German slagge, a word for the dross or refuse left over when metal is smelted. The German term is generally linked to the verb slagen, meaning 'to strike' or 'to slay', the idea being the bits of waste that are struck or beaten off the molten metal during working. From this industrial origin the word kept its core meaning of the stony residue produced in furnaces, and it later spread to volcanic and mining contexts. In British English it took on slang lives well after its technical sense: as a verb in 'slag off' (to criticise harshly), and as a coarse insult for a person. The spelling has stayed short and phonetic throughout, which keeps it an easy word to write even as its meanings multiplied.

How the word is built

• slag (from Middle Low German slagge: dross, waste struck off metal)