validation

noun

1. The act of validating something
2. Something, such as a certificate, that validates something; attestation, authentication, confirmation, proof or verification
3. The process whereby others confirm the validity of one's emotions
4. (US) The process of identifying a new prisoner's gang affiliation
5. legal process in the United States where criminal justice authorities designate that a person is a member of a gang
6. the testing of a previous observation with an expectation of confirmation