Prove to is a phrasal verb that means to demonstrate or establish the truth or accuracy of something. Some synonyms for this verb include demonstrate, establish, validate, affirm, attest, corroborate, verify, authenticate, and justify. These words are commonly used in academic writing, legal proceedings, scientific research, and other contexts where it is important to provide evidence that supports a claim or argument. Using synonyms for prove to can help to add variety and precision to your writing, and can also help to avoid repetitive or casual language.