The loose skin around the neck of an animal, especially a dog.
Scruffs are usually a comfortable place for a dog to be petted.
Examples:
The dog's collar was too tight around its scruffs.
I like to scratch my dog's scruffs.
The dog's scruffs are very fluffy.
The dog's scruffs are like a built-in pillow.
The dog's scruffs are so big, it looks like it has two heads.
The dog's scruffs are the best place to give it a hug.