It’s a term Donald Trump thrust into global attention in his press conference yesterday.
In the meeting with members of the media, he said both sides had been to blame for the incident in Charlottesville – the now-familiar 'alt-right', an amorphous group whose members straddle the political spectrum from staunch social conservatives to Neo-Nazis, and a hitherto little-known political movement: the 'alt-left.'
The US President claimed members of this group had charged at the white supremacists with clubs, and had previously said there was violence on both sides.
But who are these mysterious 'alt-left' characters? And are they as violent as Trump seems to think?
Essentially, the principle of the so-called ‘alt-left’ would be the direct opposite of those who follow the right. As opposed to the anti-Semitism, homophobia, white nationalism, anti-immigrant and anti-feminist views which formulate alt-right, alt-left must, by definition, be extremely, aggressively in favour of immigrants, LGBT rights, feminism, and equality.
When he was talking about the alt-left, Trump was almost certainly referring to groups such as Black Lives Matter, an anarchist movement which officially received its name in the wake of the acquittal of a man for the fatal shooting of a 17-year-old black teenager called Trayvon Martin in 2013.
It has since gained momentum following shootings across America, notably Michael Brown in Ferguson, Missouri. The group's calls for uprisings and its open contempt for the police have earned a torrent of opprobrium for critics who say it is only inflaming racial tensions and seeking to detonate the powderkeg for its own ends.
Another movement which was undoubtedly in Trump's sights was Antifa, an umbrella organisation for hard-left groups with roots in the punk movement, whose name is short for Anti-Fascist Action.
The movement can actually trace its lineage all the way back to 1930s Germany, originating in Germany to oppose Adolf Hitler and the Nazi Party. Today its message is firmly left of centre: one of the organisers, Scott Crow, describes himself as an anarchist on Twitter.
Antifa adherents can certainly look fairly violent: wearing masks and wielding weapons, they could easily be confused with the white nationalists they purport to despise. The movement has been criticised for damaging property during protests, and employing radical tactics to spread their message.
David Duke, a former leader of the alt-right Ku Klux Klan, named both of these groups in a tweet to thank the President for “telling the truth.” In this post, he called them “leftist terrorists.”
But there are plenty of other groups one could throw into the alt-left pot, from the international protest group Occupy to hacktivist group Anonymous, which has threatened the white nationalists responsible for Charlottesville with cyber-reprisals. It's really all about your own personal definition.
Some people think the term 'alt-left' is meaningless, that it is an illuision made up by people with far-right views to create the sense of a similar movement on the left sides of politics. Mark Pitcavage, an analyst at the Anti-Defamation League's Center on Extremism, told American news media the term was nothing more than an “insult” and didn’t refer to any actual network or movement.
Now, however, it's very much outrage. Trump's views may be wide of the mark, but he has given his 'alt-left' a form of legitimacy. One can expect the term to gain ever more credence as America's troubles continue.