Have you ever felt in low spirits and struggled to find an appropriate word to describe how you feel? I would like to suggest mubblefubbles as an option. It is considered to be obsolete but I think it’s a suitably expressive word for a difficult to verbalise feeling.
Mubblefubbles means a state of depression, melancholy or despondency. It’s quite often used in the form of to be in (or out of) one’s mubblefubbles.
The OED’s first recorded usage is from 1589 but the word’s origins are unclear. It could be imitative and I suspect the alternative form mumblefubbles may support this idea.
“‘I never used to be so full of the mubblefubbles,’ he told me wryly. ‘So fearful, so bitter—but the days when I was—when I was myself—seem so long ago that I can hardly remember them.'”
– Nancy Springer, The Golden Swan, 2014