Top definition
A person who is beautiful, but who always says something stupid/crazy/annoying. He/she is called such, because, much like 911, when he/she opens his/her mouth, the whole world changes.
I love to look at Mary, but when she opens her mouth, i lose all interest.

dude, she's a 911-mouth.
by apoxy April 27, 2012
Get the mug
Get a 911-mouth mug for your guy Riley.