Entertainment seen in ancient era, bacchanalian, recalled (7)
I believe the answer is:
cabaret
'entertainment' is the definition.
(I know that cabaret is a type of show)
'in ancient era bacchanalian recalled' is the wordplay.
'in' says the answer is hidden in the clue.
'recalled' shows that the letters should be reversed in order.
'terabac' can be found hidden inside 'ancient era bacchanalian'.
'terabac' reversed gives 'CABARET'.
'seen' acts as a link.
(Other definitions for cabaret that I've seen before include "Stage show" , "Bear cat (anag.)" , "Nightclub 12ac" , "Bob Fosse musical with Liza Minnelli" , "Liza Minnelli's entertainment?" .)