Verbs

(v)attest, certify, manifest, demonstrate, evidenceprovide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes“His high fever attested to his illness”, “The buildings in Rome manifest a high level of architectural sophistication”, “This decision demonstrates his sense of fairness”
(v)certifyguarantee payment on; of checks
(v)license, licence, certifyauthorize officially“I am licensed to practice law in this state”
(v)certify, endorse, indorseguarantee as meeting a certain standard“certified grade AAA meat”
(v)certifydeclare legally insane