sausage vs hot dog

sausage and hot dog both are nouns.

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

As nouns, hot dog is a hyponym of sausage; that is, hot dog is a word with a more specific, narrower meaning than sausage:

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

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