what is the gaming term for a temporary increase in power, speed, or other abilities
The gaming term you’re looking for is “Boost.”
In many modern games and in Dropee’s “Question of the Day,” a temporary increase in power, speed, or other abilities is specifically referred to as a boost. In broader gaming culture, you’ll also hear players casually call similar effects a power-up or a buff , but for this exact phrasing, boost is the accepted answer.
TL;DR: The correct term is boost.