hot dog vs sausage

hot dog and sausage both are nouns.

Word	Noun	Adjective	Verb	Adverb
hot dog	Yes	No	No	No
sausage	Yes	No	No	No

As nouns, sausage is a hypernym of hot dog; that is, sausage is a word with a broader meaning than hot dog:

hot dog: a smooth-textured sausage of minced beef or pork usually smoked; often served on a bread roll
sausage: highly seasoned minced meat stuffed in casings

hot dog (noun)	sausage (noun)
a smooth-textured sausage of minced beef or pork usually smoked; often served on a bread roll	a small nonrigid airship used for observation or as a barrage balloon
a frankfurter served hot on a bun	highly seasoned minced meat stuffed in casings
someone who performs dangerous stunts to attract attention to himself