Staggering, drunk nun isn't good (8)
I believe the answer is:
stunning
'staggering' is the definition.
(thesaurus)
'drunk nun isn't good' is the wordplay.
'drunk' is an anagram indicator.
'good' becomes 'g' (abbreviation).
'nun'+'isnt'='nunisnt'
'nunisnt' is an anagram of 'stunnin'.
'stunnin'+'g'='STUNNING'
(Other definitions for stunning that I've seen before include "Fantastic" , "Drop-dead gorgeous" , "Very attractive (informal)" , "Strikingly beautiful or attractive" , "Beautiful - causing insensibility" .)