Anna's boyfriend concealed a court order (4)
I believe the answer is:
asbo
'a court order' is the definition.
(ASBO is short for anti-social behaviour order)
'anna's boyfriend concealed' is the wordplay.
'concealed' says the answer is hidden in the clue.
'ASBO' can be found hidden inside 'annas boyfriend'.
(Other definitions for asbo that I've seen before include "Sanction for bad behaviour (init.)" , "Restrictive order" , "Award for bad behaviour?" , "Acronym for a legal restraint" , "One which could restrict motion" .)