cocker spaniel vs spaniel

cocker spaniel and spaniel both are nouns.

Word	Noun	Adjective	Verb	Adverb
cocker spaniel	Yes	No	No	No
spaniel	Yes	No	No	No

As nouns, spaniel is a hypernym of cocker spaniel; that is, spaniel is a word with a broader meaning than cocker spaniel:

cocker spaniel: a small breed with wavy silky hair; originally developed in England
spaniel: any of several breeds of small to medium-sized gun dogs with a long silky coat and long frilled ears

cocker spaniel (noun)	spaniel (noun)
a small breed with wavy silky hair; originally developed in England	any of several breeds of small to medium-sized gun dogs with a long silky coat and long frilled ears