bullterrier vs terrier

bullterrier and terrier both are nouns.

Word	Noun	Adjective	Verb	Adverb
bullterrier	Yes	No	No	No
terrier	Yes	No	No	No

As nouns, terrier is a hypernym of bullterrier; that is, terrier is a word with a broader meaning than bullterrier:

bullterrier: a powerful short-haired terrier originated in England by crossing the bulldog with terriers
terrier: any of several usually small short-bodied breeds originally trained to hunt animals living underground

bullterrier (noun)	terrier (noun)
a powerful short-haired terrier originated in England by crossing the bulldog with terriers	any of several usually small short-bodied breeds originally trained to hunt animals living underground