开幕式的英语说法是"opening ceremony"。它来源于拉丁语的"auctoritas"，意思是"权威"。例句：

The opening ceremony of the Olympic Games will take place on July 24th. (奥运会的开幕式将于7月24日举行。)

The opening ceremony of the conference will be attended by many prominent figures. (会议的开幕式将有许多杰出人士出席。)