broadcast vs chat show

broadcast and chat show both are nouns.

Word	Noun	Adjective	Verb	Adverb
broadcast	Yes	No	Yes	No
chat show	Yes	No	No	No

As nouns, chat show is a hyponym of broadcast; that is, chat show is a word with a more specific, narrower meaning than broadcast:

broadcast: a radio or television show
chat show: a program during which well-known people discuss a topic or answer questions telephoned in by the audience

broadcast (noun)	chat show (noun)
message that is transmitted by radio or television	a program during which well-known people discuss a topic or answer questions telephoned in by the audience
a radio or television show

broadcast (verb)	chat show (verb)
cause to become widely known
broadcast over the airwaves, as in radio or television
sow over a wide area, especially by hand