To vanquish means to defeat someone or something completely and decisively. When a chess player vanquishes their opponent, they dominate the game so thoroughly that victory is unmistakable. When a hero in a story vanquishes a dragon, the dragon is utterly defeated.

The word carries a sense of triumph and finality. You might beat someone at checkers, but you vanquish them when the victory is total and impressive. A soccer team that wins 1-0 wins the game, but a team that wins 7-0 vanquishes its opponent.

Beyond physical contests, you can vanquish fears, obstacles, or bad habits. When you finally vanquish your fear of public speaking by delivering a confident presentation, you've conquered something that once seemed impossible to overcome. Scientists work to vanquish diseases. Inventors vanquish technical problems that have stumped others for years.

You'll often encounter it in historical writing, adventure stories, and descriptions of significant victories.