Last of the golden days (3)
I believe the answer is:
end
'last' is the definition.
(thesaurus)
'of the golden days' is the wordplay.
'of' says the answer is hidden in the clue.
'END' can be found hidden inside 'golden days'.
(Other definitions for end that I've seen before include "Extremity" , "For Chelsea or Villa, it's a" , "Goal; destruction" , "Time to break-up (3,2,4) - See 12" , "Fine" .)