The outdoor event was called off because of the storm.

called 是动词 call 的过去式，call 的基本意思是"呼叫、称呼"。 off 是副词，表示"离开、中断"的意思。 called off 是一个固定短语，意思是"取消"，指原本计划好的活动或事件不再进行。