Unrivalled means having no equal or competitor, being the absolute best at something with no one else even close. When something is unrivalled, it stands alone at the top.

A chess grandmaster with an unrivalled understanding of strategy sees patterns and possibilities that others miss entirely. A restaurant known for its unrivalled pizza serves pizza so exceptional that other pizzerias can't match it. The word suggests complete dominance, like a champion sprinter whose speed is unrivalled because she consistently finishes seconds ahead of everyone else.

You'll often see this word in British English spelled this way, while Americans typically write it as “unrivaled” with one L. Both spellings mean exactly the same thing.

When scientists describe Newton's unrivalled contributions to physics, they mean his insights were so profound that no one else came close during his era. When a baker claims her grandmother's recipe is unrivalled, she's saying it's simply the best.

Unrivalled implies excellence so complete that comparisons seem almost pointless. It's the difference between being very good and being in a category of your own.