expulsion vs banishment

expulsion and banishment both are nouns.

Word	Noun	Adjective	Verb	Adverb
expulsion	Yes	No	No	No
banishment	Yes	No	No	No

As nouns, banishment is a hypernym of expulsion; that is, banishment is a word with a broader meaning than expulsion:

expulsion: the act of forcing out someone or something
banishment: rejection by means of an act of banishing or proscribing someone

Other hypernyms of expulsion include proscription.

expulsion (noun)	banishment (noun)
the act of expelling or projecting or ejecting	rejection by means of an act of banishing or proscribing someone
the act of forcing out someone or something	the state of being banished or ostracized (excluded from society by general consent)
squeezing out by applying pressure