a. used towards someone when someone else is mad, but not really that mad, at them for something silly.
b. gooey stuff in your nose that is nice for flinging at people or just eating.
c. used to call a cute little kid.
b.Teacher: "Timmy! What did you just throw at Susan?!"
Timmy: "Aww, jee Mrs. Lemonbottom, it was only a booger."
The kid felt so secluded in the class that he forgot he wasn't alone and stuck that booger right down his throat.
c. Grandma, "My sweet little booger!"
"Man I can't stand this guy he won't go away!"