They're referencing a short squeeze, the act of increasing...

They're referencing a short squeeze, the act of increasing demand for a stock so rapidly that shorters are forced to cover their short position by purchasing on market, the more shorts on a stock the bigger the effect because more shorts start covering their positions.
https://en.wikipedia.org/wiki/Short_squeeze
People have been obsessed with the idea of organising large squeezes online since the 2021 GameStop event. However that was a very different situation, and had a huge crowd behind it.

Looking at the MMA petition, I doubt they'll get any traction behind it. As they say in the petition, the brokers aren't shorting the stock so really all they're suggesting is people piling onto the stock at once to drive the price up towards the options exercise price... It's not a squeeze at all. The only reason it's made its way here is because OCC shares the same broker.