The singer performed a showstopping solo dance that captivated the entire audience.

showstopping 是由 show（表演）和 stop（停止）加上现在分词后缀 -ing 组成的复合形容词。字面意思是"让表演停止的"，引申为"精彩到让观众忘记其他表演的"，即"惊艳全场的"、"令人叹为观止的"。