I think that colloquially this word is used both by the left and the right to suggest the political tactic based on the sensibility that the political system is near collapse and attempts to "repair" the system from within are futile. Accelerationists are frustrated with the current system's perceived corruption, injustice, and immovability, thinking that acting in good faith will never attain the progress they aim for. They suggest that it is more valuable to push society and the political system to the point of collapse in attempts to incite a revolution, expecting that rebuilding the system from scratch, or at least in a society in chaos, will allow them to achieve their political goals in the new order.
Accelerationism seems to be the motive for a bunch of terrorism. For example, the Christchurch shooter cited as part of his motives wanting to spur debates on gun control, especially in the US, recognizing that these debates are increasingly dividing the country and pushing the country towards a civil war. Dylan Roof wanted to incite a race war. A lot of Islamic terror is trying to incite a pan-Islamic revolution. Antifa riots, destroys property, and often directly engages with police and right-wing groups in an attempt to weaken the "capitalist" social order.