Increase in disorder is expected (4)
I believe the answer is:
rise
'increase' is the definition.
(I know that rise is a type of increase)
'in disorder is expected' is the wordplay.
'in' says the answer is hidden in the clue.
'RISE' is hidden in the letters of 'disorder is expected'.
(Other definitions for rise that I've seen before include "more money" , "Ascent" , "Rebel" , "success" , "Get or stand up" .)