Gay terminology. Similar to a bottom, but a specific variety. A power bottom tends to be in charge, and feels most powerful when bottoming; the one who bottoms is the one on the “throne” so to speak, “taking” the Top.

Contrary to some definitions, top/bottom terms apply to all same-gender partners, and is frequently used by not only gay men but also e.g. lesbian couples.
Person A: I think I might be a verse and not a bottom.
Person B: You sure you’re not a power bottom?
Person A: A what?
Person B: (explains definition)
Person A: Oml, I think you might be right.

Person C: I-I’m kind of shy, and… I’m not sure what I’m doing… But I would love it if you came over tonight and rode me uguu uwu
Person D: (power bottom voice) U wanna see thru time binch? Turn ur location on sis I ain’t fucking around this ass HUNGRY