First victim woman beheaded (4)
I believe the answer is:
abel
'first victim' is the definition.
(Abel was murdered by his brother Cain in the Bible)
'woman beheaded' is the wordplay.
I cannot really see how this works, but
'woman' could be 'bel' and 'bel' is found in the answer.
A single letter 'a' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for abel that I've seen before include "Cornish city" , "Cain's 11" , "The Third Man" , "One of the first children" , "done in before anyone else" .)