Awesome rogue has nothing to confess (8)
I believe the answer is:
imposing
'awesome' is the definition.
(thesaurus)
'rogue has nothing to confess' is the wordplay.
'rogue' becomes 'imp'.
'has nothing' becomes 'o' (I've seen this in other clues).
'to confess' becomes 'sing' (I've seen this before).
'imp'+'o'+'sing'='IMPOSING'
(Other definitions for imposing that I've seen before include "Enormous - levying - striking" , "Impressive in appearance" , "Dictating; impressive" , "Majestic" , "Impressive - or putting tax on" .)