certify

Verb

• declare legally insane

• guarantee as meeting a certain standard
  • certified grade AAA meat
    

• authorize officially
  • I am licensed to practice law in this state
    

• guarantee payment on; of checks

• provide 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
    

Related words

• Synonyms: 
  endorse , indorse , license , licence , attest , manifest , demonstrate , evidence
• Antonyms: 
  decertify , derecognize , derecognise