Crime in casinos ramped up (5)
I believe the answer is:
arson
'crime' is the definition.
(crime of illegally starting a fire)
'in casinos ramped up' is the wordplay.
'in' indicates a hidden word.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'nosra' is hidden within 'casinos ramped'.
'nosra' in reverse letter order is 'ARSON'.
(Other definitions for arson that I've seen before include "It may get you in court" , "Criminal pyromania" , "Incendiary act" , "Incendiarism" , "Torching" .)