person licensed by the state to perform acts in legal affairs, in particular witnessing signatures on documents

A notary is a person who has learned some laws and has been appointed by a government to do some certain things using those laws. A notary is most often used to witness signatures on legal papers. A notary does this to help stop fraud and to help a person prove that they are who they say they are. Notaries in some locations can also perform marriage ceremonies.

A notary at work