babbity scrowl
A stupid noise people make when they can't think of anything to say and don't want to try harder. It sounds like a mix of a goat and a broken blender.
'Babbity scrowl!' he yelled, then sat down and stared at the wall.
'Babbity scrowl?' she said, like it was the worst thing ever.
He just said 'babbity scrowl' and left. No explanation.