We had a short pre-show activity before the performance.

pre-show 是由前缀 pre-（表示"在...之前"）和名词 show（表演）组成的复合词，字面意思是"表演前的"。 pre-show activity 指正式表演开始前进行的暖场活动，目的是活跃气氛或让观众做好准备。