Dog and Pug-dog

Dog noun - A domestic mammal that is related to the wolves and foxes.

Pug-dog and dog are semantically related. In some cases you can replace phrase "Pug-dog" with "Dog", this terms are similar.

Nearby Words: doghouse, doggy, doge

Pug-dog noun - Small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle.

Dog and pug-dog are semantically related. You can use "Dog" instead a noun phrase "Pug-dog".