Yuckiness is the quality of being disgusting or gross.
Yuckiness is usually bad because it means something is really gross or unpleasant.
Examples:
The yuckiness of the slimy frog made me shiver.
I don't like the yuckiness of the mushy banana.
The yuckiness of the dirty water made me feel sick.
The yuckiness of the gooey slime was too much for me.
The yuckiness of the stinky cheese filled the whole room.
The yuckiness of the squishy bug made me scream.