reinforcement
/ˌriːjənˈfoɚsmənt/
noun
plural -ments
reinforcements [plural] :people and supplies that are sent to help or support an army, military force, etc.
[noncount] :the act of strengthening or encouraging something
[count] :a thing that strengthens or encourages something
a response to someone's behavior that is intended to make that person more likely to behave that way again [count]