Definition of "certify"

certify

/ˈsɜː.tɪ.faɪ/

verb
third-person singular simple present certifies, present participle certifying, simple past and past participle certified
1. (transitive) To attest to (a fact) as the truth.
2. (transitive, law) To authenticate or verify in writing.
3. (transitive) To attest that a product, service, organization, or person has met an official standard.
4. (transitive, archaic) To inform; to tell (a person) that something is true.
  Quotations
  Our deeds do us three manners of service. First, they certify us that we are heirs of everlasting life, and that the Spirit of God, which is the earnest thereof, is in us.
  1847, The Church of England Magazine, volume 23, page 239
5. (archaic, reflexive) To assure (oneself) of something; to ascertain.
  Quotations
  After having certified himself of her own good health, he very kindly inquired about her mother and Miss Sophy […] .
  1751, [Tobias] Smollett, The Adventures of Peregrine Pickle […], volumes (please specify |volume=I to IV), London: Harrison and Co., […]