Hold back; control (8)
I believe the answer is:
restrain
This clue is a double definition.
'hold back' is the first definition.
(I know that hold back can be written as restrain)
'control' is the second definition.
(synonyms)
(Other definitions for restrain that I've seen before include "Keep in check" , "Limit" , "Stop" , "Hold back, tether" , "Prevent (from excess)" .)