Definition of "Reinforcement" :

noun: a military operation (often involving new supplies of men and materiel) to strengthen a military force or aid in the performance of its mission

noun: an act performed to strengthen approved behavior

noun: a device designed to provide additional strength

"He used gummed reinforcements to hold the page in his notebook."

noun: (psychology) a stimulus that strengthens or weakens the behavior that produced it

noun: information that makes more forcible or convincing

"His gestures provided eloquent reinforcement for his complaints."