Plenipotent is an adjective that means invested with or possessing full power.

The Latin word plenus (PLAY noose) means ‘full,’ while pontentia (poe TENT ee uh) — also Latin — means ‘power.’ Here’s an example of plenipotent in use:

When Mr. Kemp was plenipotent, he struck fear into the hearts of all his employees. But these days, he’s so powerless that nobody pays his threats any attention.