Commence/kəˈmens/ Definition 1 of 2Pro Tip 1/3Event Kickoff Often signals the official beginning of public events or functions. The festival will commence with a firework display. Pro Tip 2/3Formal Settings More commonly used in formal or ceremonial contexts than 'start'. Please take your seats, the ceremony will commence shortly. Pro Tip 3/3Speech Introductions Used to introduce the beginning of speeches and presentations. Ladies and Gentlemen, we shall commence with the keynote address.