'strike down' definitions:

Definition of 'strike down'

(from WordNet)
verb
Declare null and void; make ineffective; "Cancel the election results"; "strike down a law" [syn: cancel, strike down]
verb
Cause to die, especially suddenly; "The disease struck down many young men in the village"
verb
Cause to fall by or as if by delivering a blow; "strike down a tree"; "Lightning struck down the hikers" [syn: fell, drop, strike down, cut down]