Dance held among aged is conga (5)
I believe the answer is:
disco
'dance' is the definition.
(disco can mean a dance event)
'held among aged is conga' is the wordplay.
'held' indicates a hidden word.
'DISCO' is hidden in the letters of 'among aged is conga'.
(Other definitions for disco that I've seen before include "1970s' musical genre" , "Music genre - dance venue" , "equipment for playing recordings" , "Modern dance hall or event, in brief" , "Dance hall - music by Donna Summer and the Bee Gees, say" .)