Death of Cavendish (3)
I believe the answer is:
end
'death' is the definition.
(synonyms)
'of cavendish' is the wordplay.
'of' indicates a hidden word.
'END' is hidden in the letters of 'cavendish'.
(Other definitions for end that I've seen before include "Climax" , "Aim or goal" , "Butt" , "Conclusion or goal" , "Final part" .)