Delight shown by beheaded kinsman (7)
I believe the answer is:
'delight' is the definition.
(I've seen this before)
'beheaded kinsman' is the wordplay.
'beheaded' means to remove the first letter (the head of the word is removed).
'kinsman' becomes 'relation' (I've seen this before).
'relation' with its first letter taken off is 'ELATION'.
'shown by' acts as a link.
(Other definitions for elation that I've seen before include "exhibits successful pride" , "Exaltation" , "Euphoria of toenail" , "Great happiness and exhilaration" , "Feeling of joy and pride" .)