broadcast vs episode

broadcast and episode both are nouns.

Word	Noun	Adjective	Verb	Adverb
broadcast	Yes	No	Yes	No
episode	Yes	No	No	No

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

broadcast (noun)	episode (noun)
message that is transmitted by radio or television	film consisting of a succession of related shots that develop a given subject in a movie
a radio or television show	a part of a broadcast serial
	a brief section of a literary or dramatic work that forms part of a connected series
	a happening that is distinctive in a series of related events

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