1. bunny means asshole. it is used to describe someone, or describe someone's entryway to their colon.
2. bunny is also known to be the furry little creature with big floppy ears that hops around and eats grass.
3. bunny can also be a nickname.
"Anthony can be such a fuckin bunny sometimes but i love him anyway."
"Last night he fucked my bunny till i bled. It was awesome! I came 5 times."
"Oooh look! A bunny! I shall name him Bugs."