Confirm (verb)

1. To establish the truth or correctness of something.
2. To make something valid or binding by formal assent.
3. To give support or evidence to something.

Origin:

Late middle english: from old french confirmer, from latin confirmare "strengthen, ratify", from con- "together" + firmare "make firm".

Examples:

1. The test results confirmed that he had the disease.
2. The contract was confirmed by both parties signing it.
3. The witness confirmed the testimony of the previous speaker.
4. The company confirmed the layoff of 500 employees.
5. The findings of the study confirmed the hypothesis.