episode vs natural event

episode and natural event both are nouns.

Word	Noun	Adjective	Verb	Adverb
episode	Yes	No	No	No
natural event	Yes	No	No	No

As nouns, natural event is a hypernym of episode; that is, natural event is a word with a broader meaning than episode:

Other hypernyms of episode include happening, occurrence, occurrent.

episode (noun)	natural event (noun)
film consisting of a succession of related shots that develop a given subject in a movie	an event that happens
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