1. cause to fall by a blow 擊倒
The man struck down by lightning during the storm was taken to the hospital. 在暴風雨中被雷電擊中的人被送進了醫院。
With one blow he struck down his opponent. 他一拳就把對手擊倒。
2. make sb. unable to lead a full,active life 使受到摧殘
He was struck down by a heart attack at the age of forty. 他40歲時得了心髒病。
He is struck down with flu. 他患流感。