1-Another term for a best-friend or a broski. Someone you do everything with or talk to A LOT. Someone who you'll never let go to (or have a very hard time doing it) and can sometimes be a very bad influence.
Warning: Huge chance you're going to fall in love with him/her at some point of time.
2- A noise you make when eating.
1- Maddie: "Hey, do you know Raven? She's so cool! Does a ton of drugs though..."
Reba: "Yeah, I know her. She's my Numnums you know."
2- Jake *eating pizza* Numnums...Numnums....Numnums....