To prove something means to show that it's true by providing evidence or reasoning that convinces others beyond doubt. When a detective proves who committed a crime, she gathers fingerprints, witnesses, and facts that all point to one person. When you prove your answer in math class, you show each step of your work so anyone can see why your solution must be correct.

Proving requires evidence and demonstration. If you say you can juggle five balls, you prove it by actually juggling them in front of others. Scientists prove their theories through careful experiments that other scientists can repeat and verify. A lawyer in court must prove their case with testimony and documents, using concrete evidence rather than passionate arguments alone.

The strength of proof matters. Some things are easy to prove: you can prove it's raining by holding out your hand. Other things require careful work: mathematicians sometimes spend years proving complex theorems.

When someone says “prove it,” they're asking you to back up your words with actions or evidence.