Lamb originally slaughtered for a Hebrew prophet (5)
I believe the answer is:
elias
'a hebrew prophet' is the definition.
(another name for Elijah)
'lamb originally slaughtered' is the wordplay.
'lamb' becomes 'elia' (pseudonym of essayist Charles Lamb).
'originally' indicates taking the first letters.
The initial letter of 'slaughtered' is 's'.
'elia'+'s'='ELIAS'
'for' acts as a link.
(Other definitions for elias that I've seen before include "Fellow" , "Hebrew prophet" .)