How do you spell uugggg?

"Uugggg" is not a real word, so it doesn't have a standard spelling.

It's likely a representation of a sound, like a groan or a sigh. If you are trying to spell a specific sound, you might try to spell it phonetically, like:

* Ugh

* Ughhh

* Ooogh

* Uuhhh

It all depends on the exact sound you are trying to capture.