A word of excitement or exasperation. You might use it when you see a friend from out of town or if your friends bail from a camping trip. Supposed to say it long and drawn out like making a "moo" sound.
Definition: to bad for you or sucks to be you or just plain sucks *nice version*
Background: used by someone that is annoyed by the person they are talking with and what's to shut them up but not in an obvious and mean sounding manner, Tone of voice really makes this word work for the situation
"Man I can't believe that you told people about that"