Spoilt girl beheaded first man (4)
I believe the answer is:
adam
'first man' is the definition.
(first man in the Bible)
'spoilt girl beheaded' is the wordplay.
'spoilt' becomes 'ad' (I can't explain this - if you can you should believe this answer much more).
'girl' becomes 'Pam' (short for Pamela).
'beheaded' means to remove the first letter (the head of the word is removed).
'pam' with its initial letter taken away is 'am'.
'ad'+'am'='ADAM'
Can you help me to learn more?
(Other definitions for adam that I've seen before include "who was tempted by mate?" , "Robert-, eighteenth century Scots architect" , "Biblical first human" , "who transformed Palladian architecture?" , "Fellow" .)