Naughtiness, devilment (8)
I believe the answer is:
mischief
I believe this is a double definition.
'naughtiness' is the first definition.
(I've seen this before)
'devilment' is the second definition.
(I know that devilment can be written as mischief)
(Other definitions for mischief that I've seen before include "Playful misbehaviour" , "Hanky-panky" , "Petty misdeeds or real damage" , "nuisance" , "Wrongdoing, devilment" .)