red hot vs hotdog

red hot and hotdog both are nouns.

Word	Noun	Adjective	Verb	Adverb
red hot	Yes	No	No	No
hotdog	Yes	No	No	No

As nouns, red hot and hotdog are synonyms defined as:

Other synonyms of red hot include hot dog.

red hot (noun)	hotdog (noun)
a frankfurter served hot on a bun	a smooth-textured sausage of minced beef or pork usually smoked; often served on a bread roll
	a frankfurter served hot on a bun
	someone who performs dangerous stunts to attract attention to himself