Seventh heaven (7)
'seventh heaven' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ecstasy that I've seen before include "State of elated bliss" , "Overwhelming joy" , "State of perfect bliss" , "Modern drug associated with dance raves" , "Youth drug or unalloyed bliss" .)
(Other definitions for nirvana that I've seen before include "State of ideal happiness" , "Kurt Cobain's grunge band" , "Iran van (anag) - blissful state!" , "State of perfect happiness" , "Buddhist version of Paradise" .)