She danced a man’s head off! (6)
I believe the answer is:
salome
'head off' is the definition.
The definition suggests a singular noun which matches the answer.
'she danced a man's' is the wordplay.
'she' becomes 'sal'.
'danced a man' becomes 'ome' (I can't explain this - if you can you should believe this answer much more).
'sal'+'ome'='SALOME'
Can you help me to learn more?
(Other definitions for salome that I've seen before include "Her dancing got her the head of John the Baptist" , "revealing play" , "Asked for the head of John the Baptist" , "Her dancing pleased Herod" , "Herod's niece in Wilde play" .)