huh uh

"No," usually said causally on topics of minor importance. It is pronounced with the voice dropping slightly, unless it's spoken with emphasis or as a joke.

Not to be confused with it's converse, "uh huh," (meaning yes) which is said with the voice rising slightly.

I can't find my glasses. Have you seen them?
Huh uh.

Are those cookies you're hiding behind your back?
Huh uh!