slag off
verb1
To purify by melting and removing slag.
- There is a lot of copper oxide, but I can remove that by melting everything and slagging it off.
2
Commonwealth, Ireland, UK, Slang To talk insultingly to or about someone or something; usually one who is not present.
- I am forever slagging off some poor harmless dude or pitiful demented twitcher[.]1983, Bill Oddie, Gone Birding, London: Methuen, page 1:
- There’s pressure to be a brand. I’m even locked out of my social media because I just get drunk and slag people off.2023 February 24, Michael Segalov, quoting Will Young, “Will Young: ‘I’m locked out of my social media because I get drunk and slag people off’”, in The Guardian, →ISSN:
1 more example
- The Donald didn’t seem convinced and started slagging off the London mayor, Sadiq Khan. “He’s a friend of mine,” squeaked Starmer.2025 July 28, John Crace, “Sidekick Starmer can’t get a word in as The Donald dominates world’s most one-sided double act”, in The Guardian, →ISSN: