Bobtail and Sheepdog

Bobtail noun - Large sheepdog with a profuse shaggy bluish-grey-and-white coat and short tail; believed to trace back to the Roman occupation of Britain.

Sheepdog and bobtail are semantically related. In some cases you can use "Sheepdog" instead a noun "Bobtail".

Sheepdog noun - Any of various usually long-haired breeds of dog reared to herd and guard sheep.

Bobtail and sheepdog are semantically related. Sometimes you can replace term "Bobtail" with "Sheepdog", this nouns are similar.