na na nu nu
A silly word from some ancient language used when someone was surprised and had no idea what to say, so they just said 'na na nu nu' like a confused baby.
My mom said 'na na nu nu' when I told her I failed my test.
My teacher said 'na na nu nu' when I showed up dressed as a chicken.
My dog said 'na na nu nu' when I threw a couch at him.