hot dog vs sandwich

hot dog and sandwich both are nouns.

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

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

hot dog (noun)	sandwich (noun)
a smooth-textured sausage of minced beef or pork usually smoked; often served on a bread roll	two (or more) slices of bread with a filling between them
a frankfurter served hot on a bun
someone who performs dangerous stunts to attract attention to himself

hot dog (verb)	sandwich (verb)
	insert or squeeze tightly between two people or objects
	make into a sandwich