Order not entirely predictable (5)
I believe the answer is:
edict
'order' is the definition.
('edict' can be a synonym of 'order')
'not entirely predictable' is the wordplay.
'not entirely' says the answer is hidden in the clue.
'EDICT' is hidden within 'predictable'.
(Other definitions for edict that I've seen before include "An official command" , "Formal proclamation" , "Decree, order" , "Formal announcement" , "Legally binding proclamation" .)