Definitions of reinforcement:

• noun:   information that makes more forcible or convincing

  Example: "His gestures provided eloquent reinforcement for his complaints"

• 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

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

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