Spymaster has the leading role in roguery (8)
I believe the answer is:
mischief
'roguery' is the definition.
(synonyms)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for mischief that I've seen before include "Wrongdoing, devilment" , "nuisance" , "injury" , "bad behaviour" , "Naughtiness, trouble" .)