An expression of disgust or dislike.
The word 'yuch' is used when something is very gross or bad.
Examples:
Yuch, this food is gross.
Yuch, I don't like that bug.
This is yuch, I don't want to eat it.
Yuch, that smell is so bad!
Yuch, this slime is so sticky and gross.
Yuch, I don't want to touch that dirty water.