What is the meaning of certify?

verb

• Provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes.
  • usage: "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"
  • synonyms: attest, manifest, demonstrate, evidence
• Guarantee payment on; of checks.
• Authorize officially.
  • usage: "I am licensed to practice law in this state"
  • synonyms: license, licence
• Guarantee as meeting a certain standard.
  • usage: "certified grade AAA meat"
  • synonyms: endorse, indorse
• Declare legally insane. .