#1 strike down v. declare null and void; make ineffective; "Cancel the election results"; "strike down a law". wn
#2 strike down v. cause to die, especially suddenly; "The disease struck down many young men in the village". wn
#3 strike down v. cause to fall by or as if by delivering a blow; "strike down a tree"; "Lightning struck down the hikers". wn
vizzz