com·mence·ment 
/kəˈmɛnsmənt/ noun
plural com·mence·ments /kəˈmɛnsmənt/ noun formal 1 [noncount] : the time when something begins : beginning — usually + of ▪ They awaited the commencement of the trial. ▪ It's the first attempt at peace since the commencement [=start] of hostilities. 2 US : a ceremony during which degrees or diplomas are given to students who have graduated from a school or college [noncount] ▪ the week before commencement [=graduation] [count] ▪ A poet will speak at the commencement. — often used before another noun ▪ a commencement speech/address/ceremony ▪ commencement exercises
