In Northen England "bun" can refer to a small cake, elsewhere called a fairycake, or cupcake.
OTHER MEANINGS
"Bun" is also Internet Slang for Newbie , formed by reversing nub, that was first used on Internet forum The Source . "Bunned" has also come to mean essentially the same as Pwn ed.
" Bun " also may refer to a Hairstyle in which the hair is pulled back and tied up in the shape of a bun.