Naughty child brings sin into prominence (6)
I believe the answer is:
terror
'naughty child' is the definition.
'sin into prominence' is the wordplay.
'sin' becomes 'err' (to sin is to err morally).
'into' indicates putting letters inside.
'prominence' becomes 'tor' (I've seen this in another clue).
'err' going inside 'tor' is 'TERROR'.
'brings' acts as a link.
(Other definitions for terror that I've seen before include "consternation" , "Organised political violence" , "Extreme fright or dread" , "Alarm" , "State of extreme fear" .)