supreme
Highest or best, above all others in rank or quality.
Supreme means the highest, greatest, or most powerful of all. When something is supreme, nothing ranks above it.
In government, a supreme court is the highest court in the land. Its decisions stand above all other courts' rulings. A supreme commander leads all the military forces, with every other officer reporting up through the chain of command to that person.
The word often describes the ultimate example of a quality. A supreme athlete stands at the absolute top of their sport, performing at a level beyond all others. Supreme confidence means total certainty, without any doubt. When someone makes a supreme effort, they're giving absolutely everything they have.
You'll also hear it used for emphasis, like supreme pizza (loaded with all the toppings) or someone having supreme power (controlling everything with no limits).
When you call something supreme, you're saying nothing surpasses it. It's final, ultimate, and above all else in its category.