Wild orgies entertaining and extravagant (9)
I believe the answer is:
grandiose
'extravagant' is the definition.
(I've seen this in another clue)
'wild orgies entertaining and' is the wordplay.
'wild' indicates an anagram.
'entertaining' is an insertion indicator (inviting in, as for dinner).
'orgies' is an anagram of 'griose'.
'griose' enclosing 'and' is 'GRANDIOSE'.
(Other definitions for grandiose that I've seen before include "Pretentiously impressive" , "Pretentiously imposing -- organised (anag)" , "Ambitious" , "Planned on a magnificent scale" , "Impressive in style" .)