Broadly, the act of proving that something (e.g. a document) is true or genuine.
SBFI website, OPET/FDFA brochure, [Swiss diplomas in the EU](https://www.sbfi.admin.ch/dam/sbfi/en/dokumente/schweizer_diplomeindereuschweizerinnenundschweizerindereu.pdf.download.pdf/swiss_diplomas_intheeuswissnationalsintheeu.pdf. ) (6.3.2019).
Notarisation is the certification by a notary public that the signature appearing on a document is genuine.
‘Notarisation’ and ‘notarise’ are somewhat vague terms that can be used to refer to any process performed by a notary. The terms do not clearly signal ‘authentication’ or ‘authenticate’ in the above sense.
Based on Black’s Law Dictionary, West Group, 1999, p. 127 (6.3.2019).