Is "commencement" more common than "graduation ceremony"?
No, neither one is used more often than the other. A "graduation commencement" is actually the same thing as a graduation ceremony. Both are commonly used. A "commencement" and a "graduation ceremony" are when students formally receive a degree, such as a high school diploma or a college degree. Ex: The graduation commencement consisted of over two hundred students. Ex: The graduation ceremony lasted over two hours long. Ex: The commencement had many amazing speakers. Ex: The graduation ceremony was very boring.