Reinforcement

Noun

1. The act, process, or state of reinforcing or being reinforced.
2. A thing that reinforces.

   "There's a website that can be a good learning reinforcement."

3. Additional troops or materiel sent to support a military action.

   "Send in the reinforcements!"

4. The process whereby a behavior with desirable consequences comes to be repeated.
5. A small round white sticker placed around a punched hole in a piece of paper to prevent the binder's rings from tearing through the paper.