To commence means to begin or start, especially in a formal way. When a ceremony commences, it officially starts. When a judge says “let the trial commence,” court proceedings begin. When graduation exercises commence, students file in and the program starts.

The word carries a sense of importance or ceremony. You might start your homework, but a space shuttle launch commences with a countdown. A school day starts, but a presidential inauguration commences with formal rituals. The difference isn't in the action itself but in how significant or official it feels.

Commencement is the noun form, and it's what many schools call their graduation ceremony. This might seem backward since graduation is an ending, not a beginning, but the name recognizes that finishing school commences the next phase of your life.

You'll often find this word in announcements or formal writing: “Construction will commence in the spring” or “The concert commences at 7 PM.” In casual conversation, people usually just say “start” or “begin,” but commence adds a touch of formality or seriousness to whatever is about to happen.