Provide more support to control coercion (9)
I believe the answer is:
reinforce
'provide more support' is the definition.
I can't judge whether this defines the answer.
'control coercion' is the wordplay.
'control' becomes 'rein' (reining is a kind of controlling).
'coercion' becomes 'force' (I've seen this before).
'rein'+'force'='REINFORCE'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for reinforce that I've seen before include "provide support" , "Buttress" , "give added support" , "Strengthen or support with confrerie" , "Make stronger" .)