Murdered
'murdered' is the definition.
(archaic past tense form of 'slay')
This is all the clue.
(Other definitions for slew that I've seen before include "Move obliquely or sideways, often losing control" , "Quite a number" , "Twist sideways" , "Killed (arch.)" , "Killed - swing" .)
'murdered' is the definition.
('slay' can be a synonym of 'murder')
This is the entire clue.
(Other definitions for slain that I've seen before include "Violently killed" , "Killed, murdered" , "Put to the sword" , "Slaughtered" .)