The word you say when you
run your finger in between the mouth and the
nose, where a moustache would grow. You do this to someone just for
fun.
Josh walked up to Jesse and
ran his finger by his face while saying, "Moostache."
Robert walked by Josh and
ran his finger by his face while saying, "Moostache."
Josh walked by Claudia and ren his finger by her face while saying, "Moostache."