1. officially recognized as meeting certain standards or requirements
2. guaranteed to be true or genuine; verified
3. having an official document that proves qualifications or competence

Examples

• She is a certified public accountant with ten years of experience.
• The mechanic showed us his certified repair credentials.
• Only certified organic products can display this label.
• The document must be certified by a notary public.
• He became a certified scuba diving instructor last summer.
• The school requires certified teachers for all positions.
• This is a certified copy of the original birth certificate.