hot air vs empty words

hot air and empty words both are nouns.

Word	Noun	Adjective	Verb	Adverb
hot air	Yes	No	No	No
empty words	Yes	No	No	No

As nouns, hot air and empty words are synonyms defined as:

Other synonyms of hot air include empty talk, palaver, rhetoric.

hot air (noun)	empty words (noun)
loud and confused and empty talk	loud and confused and empty talk
air that has been heated and tends to rise