This writer's nonsense is naughty (6)
I believe the answer is:
impish
'naughty' is the definition.
(I've seen this before)
'this writer's nonsense' is the wordplay.
'this writer's' becomes 'I'm' (referring to the person writing the clues).
'nonsense' becomes 'pish' (I've seen this in another clue).
'im'+'pish'='IMPISH'
'is' acts as a link.
(Other definitions for impish that I've seen before include "Mischievous like small devil" , "Wicked" , "Playful" , "saucy" , "Teasingly mischievous" .)