Showy rogues go wrong (8)
I believe the answer is:
gorgeous
'showy' is the definition.
(I've seen this before)
'rogues go wrong' is the wordplay.
'wrong' indicates an anagram.
'rogues'+'go'='roguesgo'
'roguesgo' anagrammed gives 'GORGEOUS'.
(Other definitions for gorgeous that I've seen before include "Very attractive" , "Lovely" , "Sumptuously beautiful" , "Strikingly beautiful" , "Stunning" .)