By what means he be dead perhaps? (8)
I believe the answer is:
beheaded
'by what' is the definition.
I can't tell whether this defines the answer.
'he be dead perhaps?' is the wordplay.
'perhaps?' indicates an anagram (I've seen 'perhaps' mean this).
'he'+'be'+'dead'='hebedead'
'hebedead' with letters rearranged gives 'BEHEADED'.
'means' is the link.
Can you help me to learn more?
(Other definitions for beheaded that I've seen before include "Queen Jane was" , "With the top(s) cut off" , "Guillotined" , "As were two wives of Henry VIII" , "Decapitated" .)